INTRODUCTION: Chylothorax is one of the complications in cardiovascular surgery. Although prolonged chylothorax leads to critical status and is associated with high mortality, its treatment has not been well established. We present a successful case of surgical treatment of chylothorax in a neonate using indocyanine green to identify the site of lymphatic leakage.

CASE PRESENTATION: The patient with complete atrioventricular septal defect, patent ductus arteriosus, pulmonary hypertension, and chromosomal abnormality with trisomy 21 underwent pulmonary artery banding and patent ductus arteriosus ligation through median sternotomy. The postoperative course was complicated with chylothorax; conservative treatment was not effective, so surgical treatment was selected. Indocyanine green was injected subcutaneously between the first and second toes on the left side 30 min before surgery to identify the site of leakage. We could detect the lymphatic leakage from the para-aortic lymph node by indocyanine green camera in the left thoracic cavity, and the leakage sites could be closed with interrupted sutures.

CONCLUSION: Identification of lymphatic leakage sites using indocyanine green could be an effective technique in the surgical treatment of chylothorax in pediatric patients.

INTRODUCTION: Signet ring cell carcinoma (SRC) of the gallbladder is a rare type of gallbladder cancer. We report a case of SRC of the gallbladder that was characterized by the diffuse presence of SRC on the gallbladder mucosa and diagnosed after cholecystectomy.

CASE PRESENTATION: A 40-year-old man was referred to our department with upper abdominal pain and vomiting. Based on the findings of blood tests, computed tomography, and magnetic resonance imaging, acute cholecystitis was suspected, and emergency laparoscopic cholecystectomy was performed. Intraoperative findings showed mild inflammation. Although the tumor remained within the mucosa, tumor cell infiltration was suspected at the edge of cystic duct pathologically. Although additional endoscopic ultrasound and endoscopic retrograde cholangiography showed that horizontal extension into the residual cholecystic duct was suspected, there was no evidence of invasion into the common bile duct, lymph node metastasis, or distant metastasis. One and a half months after cholecystectomy, the patient underwent extrahepatic bile duct resection, lymph node dissection, and bile duct jejunal anastomosis. The postoperative course was uneventful, and the patient was discharged on the 10th postoperative day. Postoperative pathological analysis showed no obvious residual tumor tissue in the common bile duct or choledochal duct margins, and no metastasis in the submitted lymph nodes. Based on the above, a diagnosis of pT1aN0M0, pStage IA SRC was made. As no lymph node metastasis was observed, it was decided to follow up the patient without initiating postoperative chemotherapy, and the patient has been recurrence-free for 12 months after surgery.

CONCLUSIONS: We describe an incidentally discovered case of intramucosal SRC diffusely spreading throughout the gallbladder after cholecystectomy for acute cholecystitis.

INTRODUCTION: A tracheal membranous injury is a known complication of tracheostomy. After esophageal resection, such injury may prove fatal. No natural buttressing of the lesion occurs, and severe sepsis and mediastinitis may occur. In these situations, a circumferential tracheal resection is the treatment of choice, sometimes on cardiopulmonary bypass. However, the outcome is not always favorable.

CASE PRESENTATION: We report a case of a long tracheal membranous wall defect (> 7cm) after esophageal resection. We successfully performed a transtracheal direct repair of the defect through a partial sternotomy, and reconstructed the ventrolateral wall with a muscle flap using the right pectoralis major muscle.

CONCLUSION: Tracheal reconstruction through a T-shaped incision and anastomotic buttressing using a pectoralis major muscle flap could prove to be useful when reconstructing a posterior tracheal wall injury, especially after esophageal resection.

INTRODUCTION: Pulmonary vein stenosis (PVS) is known as one of the chronic complications after catheter ablation for atrial fibrillation (AF). The endovascular approach is a less invasive treatment option for PVS, while pulmonary lobectomy is also chosen, especially for patients with pulmonary vein occlusion. Here, we present a case of pulmonary vein occlusion accompanied by pulmonary necrosis that was successfully treated by pulmonary lobectomy.

CASE PRESENTATION: A 65-year-old man underwent catheter ablation for AF along with administration of anticoagulants at his previous hospital. After treatment for 6 months, hemoptysis appeared, and chest computed tomography (CT) showed an infiltration shadow in the lower lobe of the left lung. The patient was admitted to the hospital, and antibiotic therapy was initiated. Despite 10 days of antibiotic therapy, there was no improvement, and the lung infiltration worsened. Therefore, on the 10th day of hospitalization, the patient was transferred to our institute. A bloody lavage fluid was obtained under a bronchoalveolar lavage, suggesting alveolar hemorrhage. Then, a contrast-enhanced chest CT scan confirmed a complete occlusion of the left inferior pulmonary vein with suspicion of pulmonary necrosis. We performed a left lower lobectomy under a video-assisted thoracic approach. The lower lobe of the left lung was dark red with a bad smell, and there was 500-ml bloody pleural fluid. Intraoperative transesophageal echocardiography showed no thrombus in the inferior pulmonary vein. The surrounding tissue of the occlusion area of pulmonary vein was sclerotic and inflammatory with firm adhesions to the vagus nerve. The inferior pulmonary vein was separated on the non-hardening peripheral side of the occlusion point using a stapler. Pathological examination confirmed multiple hemorrhagic infarctions in the parenchyma. The patient was discharged on the 8th postoperative day, and there was no recurrence of hemoptysis at 6 months postoperatively.

CONCLUSIONS: We successfully treated patients with pulmonary vein occlusion following catheter ablation through pulmonary lobectomy. While endovascular treatment is less invasive and remains the first choice for PVS, lobectomy should be considered in patients with complete occlusion, especially when accompanied by pulmonary necrosis, or in recurrent patients after endovascular treatment.

INTRODUCTION: Pleomorphic adenoma is a benign tumor that frequently occurs in the salivary glands; however, it occurs in the breast rarely. There have been few reports of breast cancer complicated by pleomorphic adenoma of the mammary gland.

CASE PRESENTATION: A 70-year-old woman was found to have a mass lesion in her left breast during a medical examination. A needle biopsy was performed, and a diagnosis of pleomorphic adenoma was made. We performed a partial mastectomy with a margin of several millimeters from the tumor. Pathological examination revealed a diagnosis of pleomorphic adenoma with ductal carcinoma in situ. The resection margin was sufficient, and the patient was followed up.

CONCLUSIONS: Pleomorphic adenoma arising in the mammary gland is difficult to differentiate from adenomyoepithelioma, mucocele-like tumor, and metaplastic carcinoma. Since the tumor can become malignant, resection with a narrow margin is recommended, along with special efforts not to damage the capsule at diagnosis.

INTRODUCTION: Cystic neutrophilic granulomatous mastitis (CNGM) is characterized by granulomas with cysts that sometimes contain bacteria in the lumen, a surrounding neutrophilic infiltrate, and Langhans giant cells. There are no universally accepted diagnostic criteria for CNGM. Corynebacterium kroppenstedtii, a Gram-positive bacillus, has been reported to cause several infections, but the exact cause remains unclear. We report our experience with a case of CNGM, thought to be due to a rare Mycobacteroides abscessus infection.

CASE PRESENTATION: We report the case of a 36-year-old Japanese woman with granulomatous mastitis due to Mycobacteroides abscessus who had not undergone surgery and was not immunosuppressed. She presented with a chief complaint of pain and swelling in her left breast for 1 month. Mammography showed asymmetrical focal increased density, and ultrasonography showed an irregular hypoechoic area in the left 3 o’clock position. Contrast-enhanced magnetic resonance imaging showed segmental non-mass-enhancement. Ultrasound-guided vacuum-assisted biopsy with pathology revealed granulomatous mastitis. Ziehl–Neelsen staining revealed red-staining bacilli. The patient was followed up for observation because her breast pain had decreased after the examination, and there was no redness or fever. However, the breast pain has not completely disappeared, and intermittent purulent discharge from the biopsy site persisted for 5 months. Hence, two 12-Fr drains were inserted along the ductal dilatation-like hypoechoic area. Imipenem, amikacin, and clarithromycin were administered for 8 days. After 8 days of this therapy, the patient developed a drug-associated rash; therefore, antimicrobial therapy was discontinued, and the drains were removed. Her symptoms improved, and magnetic resonance imaging after 1 month showed that the previous imaging findings in her left breast had disappeared. At the time of writing, 18 months have passed since treatment, and no recurrence has been observed.

CONCLUSIONS: We experienced a rare case of CNGM associated with Mycobacteroides abscessus. This case suggests that a combination of drainage and antimicrobial therapy may shorten the duration of antimicrobial therapy in CNGM.

INTRODUCTION: Patients with large Stage IV gastric cancer (GC) invading the proximal stomach find it difficult to receive not only bypass surgery but also S-1-based chemotherapy. This study aimed to show our treatment results for those GC patients using elementary diet (ED) tubes, which enabled S-1-based chemotherapy and nutrition support.

CASE PRESENTATION: We evaluated 20 patients (13 men and 7 women; median age 70 years) with large Stage IV GCs (8.7–21.9 cm) invading the proximal stomach, who were admitted due to inability to eat, treated with S-1-based chemotherapy using an ED tube. The duration from the initiation of the chemotherapy to the improvement of oral intake, changes in nutritional status, and disease-specific survival (DSS) were retrospectively investigated. Two of the 20 patients failed to complete even one cycle of chemotherapy due to severe nausea or diarrhea. The other 18 patients improved oral liquid intake after 47.5 ± 18.8 days, and 17 patients improved oral solid food intake after 54.5 ± 19.6 days from the start of chemotherapy. In addition, three patients (16.7%) could receive conversion surgery after improvement of oral intake. The median DSS of those 18 patients was 13.1 months. Serum albumin level and prognostic nutritional index (PNI) were significantly improved after about 1 month of the treatment (both P <0.0001). Improvement of serum albumin level and PNI during the first 1 month of the treatment significantly correlated with better DSS (P = 0.006, 0.01, respectively).

CONCLUSIONS: Given a high oral intake success rate, S-1-based chemotherapy using an ED tube can be a promising treatment option for large Stage IV GC with poor oral intake.

INTRODUCTION: The interest of this case lies in the exceptional and rare character of the observed association.: Meckel’s diverticulum (MD) mimicking a postoperative flange complicated by acute intestinal obstruction and malrotation by midgut volvulus.

CASE PRESENTATION: A 17-year-old black male student, with a body mass index of 28 kg/m² was admitted to the emergency department of a 4th category rural hospital, with paroxystic abdominal pain and vomiting. Medical history revealed an abdominal surgery for an umbilical hernia 3 years earlier. There was no malformation such as imperforate anus, Hirschsprung's disease, esophageal tracheal fistula, or cardiac anomaly in the medical history. An abdominal X-ray confirmed an acute intestinal obstruction showing hydroaeric levels. The diagnosis of acute intestinal obstruction on a flange was retained. A median laparotomy was performed; a solid mass-like lengthy structure mimicking postoperative flange was seen associated with midgut volvulus, while a malposition of the intestine was observed with a mesenteric band, as well as a hyperemic appendix. A 90° rotation stop of the midgut also called a complete common mesentery was in place; we then carried out a Ladd procedure. Morpho-pathological examination of the surgical specimens revealed the following: richly vascularized fibro-adipose tissues with no evidence of malignancy in the diverticular specimen, and acute pan-appendicitis with no evidence of malignancy in the appendicular specimen. The patient started to ingest food orally on the third postoperative day, and he was discharged uneventfully on the fifth day.

CONCLUSION: MD, although generally a tubular structure, may sometimes appear as a non-tubular mass during clinical examination. Intestinal obstruction due to MD associated with midgut volvulus is exceptional. Management of this association should be based on accurate knowledge of the morpho-embryological specificities during gut development.

INTRODUCTION: Gastrointestinal duplication is a rare congenital anomaly, usually occurring in childhood and rarely in adults. It is most common in the ileum, but can occur anywhere in the gastrointestinal tract from the mouth to the anus. An adult case of intestinal duplication is accompanied by non-specific symptoms and, hence, it is often difficult to establish accurate diagnosis preoperatively in adults.

CASE PRESENTATION: We experienced two cases of ileal duplication that was manifested as acute abdomen. In both cases, we performed emergency surgery with a tentative preoperative diagnosis of perforation peritonitis related to intestinal duplication. The first case was a 36-year-old male presenting with a cystic non-communicating intestinal duplication, which was perforated, causing abdominal pain. The second case was a 77-year-old male presenting with tubular communicating intestinal duplication, in which a fecal stone was fitted into the root of the duplicated intestine, and the duplicated intestine itself became abscessed, causing abdominal pain. Their postoperative courses were uneventful and the patients were discharged from hospital without any sequelae on the 5th and 10th postoperative day, respectively.

CONCLUSION: Although preoperative diagnosis is not easy, because the clinical presentation varies depending on the occurrence site, in-depth evaluation of preoperative CT images could lead to a precise diagnosis especially when considering intestinal duplication as one of the differential diagnoses of acute abdomen.

INTRODUCTION: Pancreatic mucinous cystic neoplasm (MCN) is a cystic tumor of the pancreas typically located in the pancreatic body or tail in middle-aged women. However, MCN rupture is rare. This report describes a case of MCN with spontaneous rupture during follow-up.

CASE PRESENTATION: The patient was a 34-year-old woman. Contrast-enhanced computed tomography (CECT) and magnetic resonance imaging (MRI) revealed a 130 mm multifocal cyst in the pancreatic tail. The cyst, characterized by multiple septa and cyst-in-cyst structures, was diagnosed as an MCN. Initially, the patient opted for periodic follow-ups instead of surgical resection. After a gradual increase in cyst size, surgery was scheduled approximately 1 year later. Two days before the scheduled surgery, the patient experienced unexplained lower abdominal pain. Moreover, CECT revealed a shrinking cystic mass in the pancreatic tail along with the presence of ascites, leading to a diagnosis of spontaneous rupture of the pancreatic cyst. No peritonitis was detected, and a distal pancreatectomy was performed 2 days after admission. Pathological examination confirmed that the pancreatic cyst was a noninvasive mucinous cystadenocarcinoma. The abdominal cavity contained large amounts of turbid ascites with neutrophils but no bacterial growth. Strong inflammatory changes were noted at the cyst wall disruption site. Despite the development of a pancreatic fistula (ISGPF Grade BL, Clavien–Dindo Grade II), the patient was discharged from the hospital on postoperative day 16 and remained alive and recurrence-free for 18 months after surgery.

CONCLUSION: Spontaneous rupture of an MCN is rare. In this study, we report our case and review previously published cases of MCN rupture. We also discuss the potential causes of the spontaneous rupture in our case.

INTRODUCTION: Grade B or C post-pancreatectomy acute pancreatitis (PPAP) is associated with a higher incidence of postoperative complications and mortality. The reason for this is the activation of proteolytic processes that can lead to pancreatic destruction and the activation of systemic reactions that can have adverse consequences such as systemic inflammatory response syndrome, sepsis, and death. We report a case of a patient with Grade C PPAP with walled-off necrosis (WON) who was successfully treated with necrosectomy using a step-up approach.

CASE PRESENTATION: A 73-year-old man was referred to our hospital with elevated biliary enzymes. Results of blood tests, computed tomography (CT), and magnetic resonance imaging led to the diagnosis of distal bile duct cancer. He underwent a pyloric ring-sparing pancreaticoduodenectomy with lymph node dissection. Postoperative P-AMY (pancreatic amylase) was high at 1766 U/L, and contrast-enhanced CT showed increased density of peripancreatic fatty tissue and fluid accumulation on the pancreatic resection surface, leading to the diagnosis of postoperative pancreatitis and pancreatic fistula. On postoperative day (POD) 9, continuous washing with saline solution was started through the drain at the pancreatic anastomosis. Contrast-enhanced CT showed increased fluid retention in the pancreatic body tail. On POD 43, endoscopic ultrasonography drainage was performed for pancreatic necrosis encapsulated in the retroperitoneum; however, the patient self-extracted the drainage tube. On POD 50, CT-guided drainage was performed for a retroperitoneal subcapsular abscess. On POD 69, the patient underwent necrotomy with guided retroperitoneal drainage, a drain was inserted, and continuous flushing was performed. On POD 76, fecal discharge was observed from the drain, and drainage and enterography were performed; a fistula with the colon was confirmed, and an ileal bifurcation colostomy was performed on the same day. On PODs 83, 85, and 100, endoscopic necrotomy was performed through a retroperitoneal incision wound because a contrast-enhanced CT showed a residual abscess on the gastric dorsum. The patient’s general condition improved, and his inflammatory response also improved. On POD 139, the patient was transferred for rehabilitation.

CONCLUSION: We describe a case of successful postoperative nutritional management and necrosectomy for Grade C PPAP leading to WON.

INTRODUCTION: Surgical repair of severe perineal tears is required immediately postpartum. Owing to their low prevalence, the post-treatment course of severe tears is not well known. Herein, we report a rare case of a young woman who underwent robot-assisted curative resection with anal preservation for a rectal neuroendocrine tumor (NET) incidentally discovered following a severe perineal tear.

CASE PRESENTATION: A 29-year-old woman experienced a severe perineal tear during the first vaginal delivery, which led to the incidental discovery of a 20-mm rectal NET. Four months after the perineal tear, the gynecology and digestive surgery teams ensured that the tear wound had completely healed and anal function was preserved. The patient underwent robot-assisted ultra-low anterior resection with lymph node dissection. The procedure was successfully completed, preserving anal function, and histopathology confirmed an NET (G2, pT2N2aM0, pStage IIIB). The patient recovered smoothly and was discharged on the seventh postoperative day.

CONCLUSIONS: Rectal surgery after severe perineal tears may be associated with scarring and fibrosis around the rectum, and precautions should be taken at the time of rectal dissection. Depending on the tumor condition, it may be advisable to perform rectal surgery several months after the tear rather than immediately after treatment for the tear.

INTRODUCTION: In laparoscopic gastrectomy, accurate marking of the lesion site is essential in determining the resection line of the stomach, owing to the lack of haptics and the direct link between negative pathological margins and prognosis. Intraoperative endoscopy may require personnel and prolong the operation time, whereas preoperative endoscopic tattooing using India ink faces problems related to the spread of ink and visibility. ZEOCLIP FS (Zeon Medical, Tokyo, Japan) is a clip made of fluorescent resin, covered by insurance since March 2019. It can be visualized from the serosal side using a near-infrared scope; however, its weak fluorescence intensity often poses viewing difficulties. Lumifinder (ADVANTEST, Tokyo, Japan) is a laparoscopic fluorescence spectrum system available for clinical use since February 2023. It can measure fluorescence intensity using a near-infrared laser and detect weak fluorescent signals. We report a case of gastric cancer in which the location of the lesion was confirmed intraoperatively using ZEOCLIP FS and Lumifinder.

CASE PRESENTATION: A man in his 80s was diagnosed with gastric cancer following an examination for anemia. Two lesions were found: a 0-IIc type (cT1) at the lesser curvature of the gastric angle and a type 1 tumor (cT2) at the anterior wall of the upper gastric body. The preoperative assessment indicated no lymph node or distant metastasis. The tumor was diagnosed as cStage I and laparoscopic distal gastrectomy was planned. Two ZEOCLIP FS clips were placed on the oral side of the tumor on the anterior wall of the upper gastric body on the day before surgery. During surgery, fluorescent signals from the clips were detected using Lumifinder, enabling easy confirmation of the lesion location and determination of the gastric resection line.

CONCLUSIONS: The combined use of ZEOCLIP FS and Lumifinder was a useful new method for identifying the appropriate resection line of the stomach. We plan to evaluate this method further in additional cases to enhance the detection efficacy.

INTRODUCTION: Immune thrombocytopenic purpura (ITP) is one of the immune-related adverse events (irAEs) related to immune checkpoint inhibitors (ICIs). Here, we report a case of a 51-year-old woman with triple-negative breast cancer (TNBC) who experienced severe thrombocytopenic purpura during the neoadjuvant chemotherapy (NAC), including pembrolizumab.

CASE PRESENTATION: A 51-year-old woman was diagnosed with Stage II B TNBC and underwent NAC using pembrolizumab + paclitaxel + carboplatin. Her blood test on cycle 4, day 15 (C4D15) showed a significant decrease in platelets to <2000/µL accompanied by overt bleeding tendency. She was hospitalized for further investigation and treatment. Her platelet count recovered after platelet concentrate transfusion and corticosteroid administration. Her bone marrow examination showed normal cellularity, and she was judged as ITP. Due to the event and good clinical response to NAC, she underwent a right partial mastectomy and axillary lymph node dissection without completion of the planned NAC. The surgical specimen showed a complete pathological response.

CONCLUSIONS: Thrombocytopenia is known as one of the hematologic irAEs; however, severe thrombocytopenia with a bleeding tendency is rarely reported. Sufficient explanations to patients and appropriate referral to other related departments are important for earlier detection and treatment of irAE.

INTRODUCTION: This case report presents the world’s first transanal total mesorectal excision (taTME) using the Senhance Digital Laparoscopy System for rectal cancer. Senhance has been gaining attention as an advanced surgical robot, providing better visualization, stable dissection, and reduced surgeon fatigue compared to conventional methods.

CASE PRESENTATION: A 68-year-old woman underwent Senhance-assisted taTME for a rectal tumor located 4 cm from the anal verge. The procedure was completed safely with a total operation time of 209 minutes, a cockpit time of 85 minutes, and a blood loss of 40 mL. Pathological evaluation confirmed complete resection (R0) with no residual cancer or lymph node metastases. The patient was discharged on postoperative day 7 without complications.

CONCLUSIONS: This case demonstrates the potential advantages of Senhance-assisted taTME, including improved visualization, stable dissection, and reduced surgeon fatigue. Further studies are needed to evaluate long-term outcomes and establish the role of this technique in rectal cancer surgery.

INTRODUCTION: Neoadjuvant, adjuvant, and perioperative immune checkpoint inhibitor (ICI) regimens for treating locally advanced lung cancer have dramatically evolved in recent years. Despite these immunotherapies being very promising, they can be associated with potential life-threatening immune-related adverse events (irAEs), and there is not much awareness regarding irAEs in surgical regimens.

CASE PRESENTATION: A Japanese man in his 70s was diagnosed with right upper lobe lung adenocarcinoma (cT3N1[#12u]M0, parietal pleural invasion, cStage IIIA), with the programmed death-ligand 1 expression level of <1%. He underwent right upper lobectomy via open thoracotomy followed by 3 cycles of neoadjuvant cisplatin, pemetrexed, and nivolumab. The pathological response rate was 50% and the pathological stage was ypT2bN0M0, ypStage IIA. Seven months after the surgery, he experienced gradually worsening anorexia, fatigue, and hyponatremia. He was diagnosed with pituitary adrenal insufficiency induced by neoadjuvant immunotherapy by the 100 μg corticotropin-releasing hormone stress test. Cardiogenic shock caused by takotsubo cardiomyopathy occurred, and intensive treatment was performed. Steroid therapy was effective, but the physical dysfunction persisted, although no recurrence of lung cancer was observed.

CONCLUSIONS: Patients receiving neoadjuvant immunotherapies can develop life-threatening irAEs late in the postoperative period. Surgeons who follow up patients after neoadjuvant immunotherapies must be as vigilant regarding the development of irAEs in the postoperative phase as clinical oncologists.

INTRODUCTION: Lung resection after open esophagectomy poses significant technical challenges, particularly when the reconstructed gastrointestinal tract is on the same side as the lung lesion. The advent of 4K 3-dimensional (3D) endoscopic systems with near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) has improved the precision of thoracic surgeries. We present a case of successful right upper lung segmentectomy for primary lung cancer after open esophagectomy, utilizing a 4K 3D endoscopic system and NIR imaging.

CASE PRESENTATION: An 85-year-old female with a history of open esophagectomy for esophageal cancer 19 years earlier and comorbidities, including aplastic anemia and diabetes mellitus, was referred for the evaluation of a growing lesion in the right upper lung. Computed tomography (CT) revealed a 43-mm tumor and the gastric tube, reconstructed during the prior esophagectomy, located in the right thoracic cavity. A CT-guided biopsy confirmed lung adenocarcinoma (cT2bN0M0, Stage IIA). Surgical challenges included severe adhesions from the previous thoracotomy and thrombocytopenia (platelet count: 20000) due to aplastic anemia. A thoracoscopic segmentectomy of the anterior segment of the right upper lobe was performed using a 4K 3D endoscopic system (TIPCAM1 Rubina; Karl Storz, Tuttlingen, Germany). Adhesions were meticulously dissected, and intraoperative platelet transfusions were administered. NIR imaging with ICG identified the intersegmental plane and confirmed blood flow to the gastric tube, preventing ischemic complications. The lung segmentectomy was completed using staplers, preserving the right gastroepiploic artery. Histopathology revealed acinar adenocarcinoma (pT3N0M0, Stage IIB). The patient resumed oral intake on postoperative Day 1 and was discharged on Day 13 without complications. No recurrence was noted during the follow-up.

CONCLUSIONS: This case demonstrates the effective use of 4K 3D endoscopic systems and NIR imaging with ICG in complex lung resections following open esophagectomy. These technologies facilitate precise dissection and blood flow assessment, which are crucial for preserving reconstructed structures and enhancing surgical safety.

INTRODUCTION: Intrahepatic cholangiocarcinoma (ICC) is a highly malignant cancer for which surgery is the only curative treatment. The prognosis of ICC is extremely poor, especially in cases of lymph node metastasis (LNM), owing to the high postoperative recurrence rate. Herein, we present a case of advanced ICC with a breast cancer susceptibility gene-2 (BRCA2) mutation, treated with preoperative chemotherapy, including cisplatin, followed by surgery, in which we achieved a pathologic complete response.

CASE PRESENTATION: A 52-year-old woman was referred to our hospital and was subsequently diagnosed with bilateral breast cancer. Computed tomography (CT) and magnetic resonance imaging incidentally detected a liver tumor in the hilar region and lymph node enlargement in the hepatoduodenal ligament. A 19 mm tumor was observed in the area surrounded by the right and left branches of the portal vein and an abnormal portal branch of segment 7. Positron emission tomography-CT showed fluorodeoxyglucose uptake in the liver tumor, hepatoduodenal ligament lymph nodes, and bilateral breasts. A tumor biopsy showed a papillary tumor, and ICC was suspected. As ICC with LNM has a poor prognosis, neoadjuvant chemotherapy was planned. Genetic testing using a blood sample revealed a BRCA2 mutation, indicating the patient would benefit from chemotherapy, particularly cisplatin. The patient received a chemotherapy regimen comprised of gemcitabine, cisplatin, and S-1 (GCS), and after 7 courses, her carbohydrate antigen 19-9 level decreased from 2433 to 15 U/mL. CT showed that the tumor had shrunk and the LNMs were indistinct. The patient was referred to our department for curative surgery, which included a left hepatectomy, caudate lobectomy, hepatoduodenal ligament lymph node dissection, bile duct resection, and choledocojejunostomy. The postoperative course was generally uneventful, and the patient was discharged on postoperative day 18. Pathological examination of the resected specimen revealed an absence of malignant cells. At 24 months postoperative, there was no evidence of recurrence.

CONCLUSIONS: We encountered a patient with advanced ICC with a BRCA2 mutation, which was successfully treated with preoperative GCS therapy followed by surgical resection, and a pathologic complete response was achieved. GCS therapy, therefore, appears promising as neoadjuvant chemotherapy for the treatment of ICC.

INTRODUCTION: The phosphatase and tensin homolog hamartoma tumor syndrome (PHTS) refers to a spectrum of disorders caused by variants of the phosphatase and tensin homolog (PTEN) gene, including Cowden syndrome (CS), Bannayan–Riley–Ruvalcaba syndrome, adult Lhermitte–Duclos disease, and autism spectrum disorders associated with macrocephaly. PHTS is characterized by hamartomas in multiple organs and is associated with an increased risk of developing malignant tumors including, breast, thyroid, endometrial, colorectal, and kidney tumors. Breast cancer is the most common malignancy associated with PHTS.

CASE PRESENTATION: We describe the case of a 44-year-old female patient with invasive ductal carcinoma of the right breast. Cobblestone papillomatosis was present in the gingiva. She had a medical history of bilateral adenomatous goiters for 10 years. Her mother had been diagnosed with breast cancer, thyroid and tongue tumors, gastric polyps, hepatic hemangioma, and collagen disease. Additionally, the patient’s maternal grandmother had a history of colon cancer. Based on the patient’s family history and physical findings, CS was suspected, and direct DNA sequencing analysis revealed a haplotype c.634del mutation in exon 7 of the PTEN gene. Although there is no clear evidence supporting risk-reducing surgery for PHTS, a right nipple-sparing mastectomy, sentinel lymph node biopsy, and tissue expander reconstruction were performed.

CONCLUSIONS: We report a case of breast cancer with a newly diagnosed c.634del mutation in the PTEN gene. We also reviewed the current literature on PTEN genetic variants and breast cancer subtypes.

INTRODUCTION: Undifferentiated sarcomas of the gastrointestinal tract are rare and have poor prognoses, especially those with lymph node metastases. There is no consensus on the treatment plan. While there are reports on undifferentiated pleomorphic sarcomas of the rectum, no reports on undifferentiated rectal spindle sarcomas with lymph node metastases have been presented previously.

CASE PRESENTATION: We report a case of a 97-year-old woman referred to our hospital with anal pain. Imaging findings indicated multiple tumors in the rectum below the peritoneal reflection protruding from the anus and two enlarged pararectal lymph nodes. Laparoscopic abdominoperineal resection of the rectal sarcomas with lymph node metastasis was performed to alleviate the pain with uneventful postoperative courses. The immunostaining did not reveal a trend of tumor cell differentiation. The tumor was diagnosed as undifferentiated spindle cell sarcoma based on histopathological findings. Because of advanced age, the patient is followed up on an outpatient basis without additional postoperative treatment.

CONCLUSION: The prognosis of undifferentiated sarcomas is poor. While radical resection is the primary treatment, the efficacy of preoperative radiation therapy, cytotoxic chemotherapy, and immune checkpoint inhibitors has been investigated recently. Accumulating cases of this disease is important to determine treatment plans, and this report is valuable in this regard.

INTRODUCTION: Metastasis to the hilar and mediastinal lymph nodes in gynecological cancer is rare, and isolated hilar or mediastinal lymph node metastases are even rarer. In this report, we describe the results of lymph node dissection performed on 3 patients with hilar mediastinal lymph node metastasis but no lung metastasis from uterine or ovarian cancer.

CASE PRESENTATION: Case 1 was a 50-year-old woman diagnosed with ovarian cancer with mediastinal lymph node metastasis. After 4 courses of chemotherapy, a total hysterectomy, omentectomy, and mediastinal lymph node dissection were performed simultaneously. The patient is still alive 58 months after surgery. Case 2 was a 68-year-old woman who underwent a total hysterectomy after chemotherapy for endometrial cancer with multiple lymph node metastases. Forty-two months after surgery, mediastinal lymph node dissection was performed for metastasis of uterine cancer. She is still alive 75 months after surgery. Case 3 was a 69-year-old woman who underwent a hysterectomy for endometrial cancer. One year after surgery, she underwent thoracoscopic hilar and mediastinal lymph node dissection due to metastasis. Thirty-nine months have passed with no recurrence. Aggressive local control, particularly surgical resection of isolated hilar mediastinal lymph nodes in gynecological cancer, may contribute to prolonging patient survival.

CONCLUSIONS: Aggressive local control, especially surgical resection, for isolated hilar mediastinal lymph nodes due to gynecological cancer is safe and may contribute to prolonging survival.

INTRODUCTION: The incidence of spontaneous regression (SR) of malignancy is one in 60000–100000 cancer patients and spontaneous regression in colorectal cancer is quite rare, reported to account for less than 2% of spontaneous regression of malignancy. In recent years, some reports of spontaneous regression in colorectal cancer in patients with high-frequency microsatellite instability have suggested a deep association between high-frequency microsatellite instability and spontaneous regression. We report our experience of spontaneous regression of advanced colorectal cancer with high-frequency microsatellite instability and provide a review of spontaneous regression in colorectal cancer.

CASE PRESENTATION: An 83-year-old woman was diagnosed as having advanced colorectal cancer in the transverse colon by lower gastrointestinal endoscopy, and biopsy results revealed moderately differentiated adenocarcinoma. Contrast-enhanced computed tomography showed a tumor located near the hepatic flexure and an enlarged lymph node near the tumor. No distant metastasis was observed, and the preoperative diagnosis was cT3N1aM0 cStage IIIb cancer. Immunohistochemical analysis of the biopsy specimen suggested deficient mismatch repair. During the wait for surgery, the patient was urgently hospitalized due to severe dehydration. After her general condition improved, 38 days after the biopsy, we performed laparoscopic resection of the partial ascending and transverse colon with D3 lymph node dissection. The tumor noted preoperatively was not present in the specimen, and intraoperative endoscopy revealed no tumor on the anorectal side. Additional ileocecal resection was performed, but no tumor was found in the specimen, and another intraoperative endoscopy was performed, which revealed a discolored scar near the anal margin. We determined that tumor loss or morphological change had occurred, so after additional resection of the same area, ultimately, an extended right hemicolectomy was performed. Histopathological diagnosis was pT0N0M0 pStage0 cancer with no residual tumor. The patient has progressed without recurrence at 1 year after the operation.

CONCLUSIONS: The immunological response due to high-frequency microsatellite instability may be related to the mechanism of spontaneous regression in colorectal cancer. If high-frequency microsatellite instability is diagnosed preoperatively, we recommend that the tumor location should be confirmed preoperatively.

INTRODUCTION: An ilio-iliac arteriovenous fistula (IIAVF) secondary to the rupture of a common iliac artery aneurysm (CIAA) is rare. Sudden arteriovenous shunting and subsequent fistula enlargement can result in acute cardiac failure. Immediate diagnosis and treatment are required; however, the clinical symptoms differ from those of a free wall rupture of an aortic aneurysm, making a quick diagnosis difficult. Thus, we reported the case of a patient with severe right-sided cardiac failure, due to an arteriovenous shunt formation secondary to an IIAVF who underwent an artificial blood vessel replacement with favorable results.

CASE PRESENTATION: A 71-year-old male patient presented to our hospital with polypnea and palpitations. Initial early-phase computed tomography (CT) revealed a 60-mm-in-diameter right CIAA and an inferior vena cava (IVC) dilatation. Severe congestive heart failure, due to an arteriovenous shunt formation secondary to an IIAVF was diagnosed. The massive shunt of blood flowed from the right common iliac artery (CIA) to the right common iliac vein (CIV). He underwent an emergency open abdominal aortic replacement. The IVC ran anomalously anterior to the giant right CIAA and strongly adhered to the IVC and right CIV. Two guidewires were inserted from the bilateral femoral veins into the IVC intraoperatively. Moreover, an occlusion balloon was inserted into the right CIV. Thus, bleeding from the fistula was well-controlled by the time of aneurysm opening. The proximal side of the artificial graft was anastomosed to the abdominal aorta, while the right and left peripheral branches of the prosthesis were anastomosed to the right external iliac artery and left CIA, respectively.

CONCLUSIONS: We reported the case of a giant right CIAA that directly created a shunt into the right CIV. Contrast-enhanced CT is a useful method for confirming the working diagnosis of an IIAVF. In particular, in cases of IVC anomalies or strong perivenous tissue adhesions, bleeding can be controlled using devices, such as occlusion balloons and a meticulous surgical plan.

INTRODUCTION: Ischemia in extra-lobar pulmonary sequestration is rare and mostly occurs in childhood; it is uncommon in adults but can be progressive, necessitating surgical removal.

CASE PRESENTATION: A 37-year-old woman experienced sudden onset severe back pain and was initially diagnosed with pneumonia. Computed tomography revealed a 4.5 cm mass on the diaphragm and rapidly increasing pleural effusion. Emergency surgery confirmed a black mass that adhered to the diaphragm, which could be bluntly detached, but one was fixed in a cord shape that was detached by an energy device. Pathology showed significant hemorrhage and tissue destruction in extra-lobar pulmonary sequestration.

CONCLUSIONS: Extra-lobar pulmonary sequestration infarction, which develops suddenly with pain as the main complaint, is rare and mainly seen in early childhood but can also occur in adults.

INTRODUCTION: Omental torsion (OT), caused by twisting of the greater omentum around its axis, leading to reduced blood supply to the distal aspect of the omentum and tissue infarction, is a rare disease that manifests clinically as acute abdominal pain. Accurate preoperative diagnosis is difficult. Here, we present 2 pediatric patients diagnosed and treated using computed tomography (CT).

CASE PRESENTATION: Case 1, a 14-year-old boy, had abdominal pain for 3 days. Upon referral to our hospital due to worsening pain, CT revealed an intra-abdominal fatty mass extending into high-density lesions in the fat tissue. Due to severe peritoneal irritation, emergency single-incision laparoscopic surgery was performed. Secondary OT was diagnosed as the greater omentum was twisted by the cord-like tissue, continuing from the greater omental infarction to the lesser omentum. Partial omentectomy, including the ischemic portion, was performed. Case 2, an 11-year-old boy, was referred with suspected appendicitis due to right lower abdominal pain for 2 days. CT revealed a whirling sign in the greater omentum and high-density lesions in the fat tissue. The patient was in good condition, and the peritoneal irritation was unclear; therefore, conservative treatment was initiated. However, symptoms did not improve after 48 h and single-incision laparoscopic surgery was performed, revealing a twisted necrotic omental mass diagnosed as primary idiopathic greater OT. Partial omentectomy, including the ischemic portion, was performed.

CONCLUSIONS: CT scan aids in preoperative diagnosis of OT, for which single-incision laparoscopic surgery is a less invasive and useful therapy. Early surgical intervention is warranted when conservative treatment fails.

INTRODUCTION: Aneurysms of peripheral foot arteries are extremely rare. Dorsalis pedis artery aneurysms account for 0.5% of peripheral artery aneurysms of the lower limbs. Here, we present a case of pseudoaneurysm of the first dorsal metatarsal artery of the foot and discuss the therapeutic strategy based on a literature review.

CASE PRESENTATION: A 76-year-old man with no history of foot trauma presented with pain and a pounding mass in the dorsum of the left foot. Echography revealed a 29 × 18 × 20 mm saccular aneurysm with to-and-fro blood flow. Contrast-enhanced computed tomography revealed an aneurysm in the first dorsal metatarsal artery. Angiography of the aneurysm revealed no arterial drainage. Embolization was subsequently performed only for the feeding artery, which was the proximal first dorsal metatarsal artery, using the 2 Target nanocoils (Stryker; Boston, MA, USA), resulting in successful occlusion. However, echography performed a few months after embolization revealed a recurrence of blood flow and enlargement of the coiled aneurysm. Nine months after embolization, the pain in the dorsum of the foot recurred. Therefore, we performed a surgical resection of the dorsal metatarsal artery aneurysm (38 × 26 × 26 mm) under general anesthesia. The first distal dorsal metatarsal artery exhibited pulsatile bleeding, and angiography of the distal dorsal metatarsal artery revealed a patent pedal arch and posterior tibial artery. Therefore, revascularization was not performed. The postoperative course was uneventful. The pathological examination indicated that the mass was a pseudoaneurysm.

CONCLUSIONS: The treatments for peripheral foot artery aneurysms include observation, thrombin injection, ultrasound compression, embolization, surgical excision, and ligation. As the long-term outcomes of embolization for such aneurysms are unknown and cases are limited, surgical excision that is safe and definitive is recommended as the first-line treatment.

INTRODUCTION: Mediastinal parathyroid cyst is a rare cystic disease that involves the parathyroid tissue within its walls. This case report is the first to document a mediastinal parathyroid cyst with recurrent laryngeal nerve paralysis and tracheal deviation that improved after surgical resection.

CASE PRESENTATION: A 47-year-old man experienced hoarseness and dyspnea upon exertion for 1 month. Computed tomography revealed a mediastinal cystic lesion with a maximum diameter of 78 mm, compressing the trachea. Laryngofiberscopy suggested long-term left recurrent laryngeal nerve paralysis. Tumor resection was performed while preserving the left recurrent laryngeal nerve. The pathological examination led to the diagnosis of a mediastinal parathyroid cyst. Postoperatively, both tracheal deviation and recurrent laryngeal nerve paralysis improved.

CONCLUSIONS: Surgical resection improved the tracheal deviation and recurrent laryngeal nerve paralysis caused by a mediastinal parathyroid cyst. Long-standing recurrent laryngeal nerve paralysis can improve, emphasizing the need for proactive surgical intervention and the importance of careful preservation of the recurrent laryngeal nerve.

INTRODUCTION: Pulmonary vein stump thrombosis can sometimes occur at the pulmonary vein stump after lung surgery, possibly causing systemic infarction. Here, we report a rare case of acute myocardial infarction (AMI) caused by pulmonary vein stump thrombosis after the left upper lobectomy.

CASE PRESENTATION: A 43-year-old male patient with a nodule in the left lingular segment was referred to our hospital. A bronchoscopic biopsy performed at the previous hospital was negative for malignancy; however, the nodule was highly suspicious of primary lung cancer. Therefore, we decided to perform a thoracoscopic lung resection for a definite diagnosis and treatment. Lingular segmentectomy was performed to diagnose the nodule, and a rapid pathological diagnosis confirmed that the nodule was an adenocarcinoma. Subsequently, a left upper lobectomy and systemic lymph node dissection were performed. The left lingular and superior segmental veins were separately dissected using a stapler. The day after the operation, the patient suddenly developed cardiac arrest. Cardiopulmonary resuscitation and venoarterial extracorporeal membrane oxygenation were immediately initiated. After the return of spontaneous circulation was obtained, contrast computed tomography was performed, which suggested thrombosis of the pulmonary vein stump without any signs of brain hemorrhage or infarction. As intermittent ventricular fibrillation persisted, the patient underwent coronary angiography and was diagnosed with AMI due to pulmonary vein stump thrombosis. The thrombosis of the coronary artery was removed using percutaneous coronary intervention. The patient recovered gradually after the intervention and was discharged 2 weeks later from the intensive care unit. One month after rehabilitation for higher brain dysfunction, the patient was discharged from our hospital without any sequelae and received adjuvant chemotherapy for lung cancer.

CONCLUSIONS: We encountered a case of AMI caused by pulmonary vein stump infarction after the left upper lobectomy. Given that this complication is rare but lethal, clinicians should consider it and take great care of the residual length of the pulmonary vein stump to prevent thrombosis.

INTRODUCTION: Intrahepatic cholangiocarcinoma (ICC) is the second most common liver malignant tumor with a poor prognosis. Lymph node (LN) metastasis is found in 15% of ICC at the time of initial diagnosis. However, the LN metastasis to the anterior mediastinum is extremely rare. Herein, we report a case of anterior mediastinal LN metastasis of ICC.

CASE PRESENTATION: The patient is a 74-year-old man who had surgery for cervical esophageal cancer. During follow-up, a low-density hepatic tumor and swollen LNs in the anterior mediastinum were detected. The tumor of the liver was diagnosed as ICC by needle biopsy. Excisional biopsy of the LN was performed and the diagnosis was metastasis of ICC. Because the prognosis of the patient with ICC Stage IVB is poor, the patient received 8 courses of chemotherapy. Although the new lesion appeared next to the main tumor, these tumors were located in the left liver. In addition, it was difficult for the patient to continue the chemotherapy due to the renal dysfunction. Hepatectomy with lymphadenectomy was performed. The patient survives without recurrence for 9 months after surgery. This is the first report of anterior mediastinal metastasis of ICC without any other organ involvement.

CONCLUSIONS: Metastasis to the anterior mediastinum of hepatic tumor can be explained by the system that lymphatic fluid running under the capsule of the liver drains to the anterior mediastinal LNs through the coronary ligament. Metastasis of ICC to mediastinal LNs can occur when the tumor is located at the surface of the liver. Excisional biopsy is effective in determining the accurate disease stage and the treatment strategy.

INTRODUCTION: The rupture of an umbilical hernia, which is known as Flood syndrome, is a rare and life-threatening complication of liver cirrhosis. Herein, we report the successful repair of a ruptured incisional hernia accompanied by liver cirrhosis.

CASE PRESENTATION: A female in her 40s with a history of alcoholic cirrhosis and ruptured acute umbilical hernia treated by primary closure 6 months earlier presented with ascites leakage from abdominal skin. She was diagnosed with a ruptured incisional hernia accompanied by massive ascites. We started preoperative management with topical corticosteroids and oral diuretics. Nine months after the first visit, hybrid herniorrhaphy, extended totally extraperitoneal transversus abdominis release (eTEP-TAR) was performed. The patient has since been well without any sign of recurrence for 2 years.

CONCLUSIONS: We experienced a successful treatment of a ruptured incisional hernia accompanied by liver cirrhosis. Preoperative management and surgical strategies are important for the treatment of ruptured incisional hernia and Flood syndrome.

INTRODUCTION: Sebaceous carcinoma (SC) is a malignant neoplasm differentiated from the mature sebocyte and occurs mainly in the periorbital area. However, SC of the breast is extremely rare. We report a case of sebaceous breast carcinoma in a Japanese man with a BRCA2 pathogenic variant.

CASE PRESENTATION: A 77-year-old Japanese man had been aware of a mass in his right breast for about a year and had visited his previous physician for a follow-up. Over the next year, the mass grew, and the last doctor he visited referred him to our hospital for further examination and treatment. Physical examination revealed a palpable 3-cm-large mass of the right breast. There was no skin invasion, and core needle biopsy revealed invasive ductal carcinoma cT2N1M0 cStage IIB, estrogen receptor (+)/progesterone receptor (+)/HER2/neu (–)/Ki-67 labeling index: 27.8%. His daughter had a history of breast cancer, and he had a BRCA2 pathogenic variant. The patient underwent a total right mastectomy and axillary lymph node dissection. Pathological diagnosis was primary SC of the breast, pT2N0M0, pStage IIA. His postoperative clinical course was good. Postoperatively, the patient received endocrine therapy and S-1 for 1 year and is currently receiving endocrine therapy alone. One year and 5 months have passed since the operation, with no recurrence or metastasis noted.

CONCLUSIONS: The prognosis of SC of the breast has not been elucidated. As cases of SC with a BRCA2 pathogenic variant are exceedingly rare, it will be necessary to continue accumulating cases in the future to understand this disease further. This research is essential to elucidating SC.

INTRODUCTION: Kartagener’s syndrome (KS) is a rare disease characterized by a triad of situs inversus totalis, chronic sinusitis, and bronchiectasis. The disorder is caused by a hereditary genetic abnormality that impairs ciliary movement. Although aberrant pass course of the inferior laryngeal nerves due to visceral inversion should be considered during thyroid surgery in patients with KS, no report of surgical treatment for Graves’ disease (GD) in patients with KS has been found to date.

CASE PRESENTATION: A Japanese male in his 40s was referred to our hospital for surgical treatment for drug-refractory GD. He was diagnosed to have KS by genetic alteration of the DNAH5 gene as well as clinical triad. No abnormal branching in the mediastinal great vessels was identified in the present case, and left-sided non-recurrent inferior laryngeal nerve (NRLN) was not observed during surgery. Previous literature has demonstrated that the presence of a right-sided aortic arch and an anomalous branch of the left subclavian artery, as well as the absence of a left ductus arteriosus demonstrable on preoperative imaging studies, are prerequisites for the development of the extremely rare left-sided NRLN.

CONCLUSION: We reported the first case of surgical treatment for GD in a patient with KS and discussed the preoperative diagnosis of NRLN.