A 60-year-old woman visited our outpatient with a chief complaint of a rapidly growing left breast mass. Mammogram and breast ultrasonography revealed a 53-mm, circumscribed, lobulated mass with coarse calcifications. Upon performing core needle biopsy, a diagnosis of breast carcinoma with osseous and cartilaginous metaplasia was made. After performing mastectomy with axillary dissection, we confirmed that the tumor had been acupied with osseous metaplasia on histopathological examination. Two months after the surgery, the tumor metastasized to the lungs. Local relapse and metastasis to the sixth cervical vertebrae occurred shortly thereafter. The patient died 130 days after the operation. Her blood alkaline phosphatase level consistently fluctuated in conjunction with the status of the cancer. Carcinomas with osseous and cartilaginous metaplasia are rare breast tumors. They often develop with resistance to chemotherapy and worse rapidly. We report this case along with a review of the literatures.

A 39-year-old woman was diagnosed with right breast cancer (invasive ductal carcinoma, triple-negative, MIB-1 labeling index of approximately 80%, T2N1M0, stage IIB). Four courses of epirubicin/cyclophosphamide were administered as neoadjuvant chemotherapy, followed by 12 courses of weekly paclitaxel. Subsequent contrast-enhanced computed tomography (CT) revealed a partial response. We speculated that radical surgery was possible and performed right mastectomy with level II axillary lymph node dissection. Histopathological examination of the surgical specimen revealed a pathological complete response. CT and magnetic resonance imaging performed 6 months post-surgery revealed brain metastasis, measuring approximately 26 mm in the right temporal lobe. Considering that she had a single brain metastasis and no metastatic lesions in other organs, we performed intracranial tumor resection followed by whole-brain irradiation. However, the patient died 2 months later. Patients with breast cancer may develop minor brain metastases, and neoadjuvant chemotherapy may have a marked effect on tumors other than those in the brain, but the administered antineoplastic drugs could not cross the blood-brain barrier. Therefore, the brain metastasis that occurred in our patient continued to develop and remained untreated but became apparent post-surgically.

A 48-year-old woman presented with a tender left supraclavicular mass. Thoracoabdominal computed tomography revealed a left supraclavicular tumor 2 cm in size and an enhanced mass in the lateral segment of the right breast. Ultrasonography revealed a left supraclavicular lobular mass and an irregular-shaped mass at the CD border in the right breast. The result of core needle biopsy (CNB) of the right breast mass was invasive ductal carcinoma and that of a fine needle aspiration cytology of the left supraclavicular mass was suspicious for malignancy. The incisional biopsy of the latter indicated node meta neuroendocrine tumor (NET) - G1, although diagnostic tests failed to identify a primary lesion. Following the excision of the NET, which resulted in the diagnosis of NET - G2. The patient underwent right mastectomy along with sentinel lymph node biopsy. The clinical course has been uneventful with the administration of tamoxifen.

We report a rare case of spontaneously occurring malignant transformation of teratoma arising in the anterior mediastinum in a 45-year-old woman. She presented with an abnormal shadow on a plain chest x-ray at a periodic medical checkup. A plain chest computed tomography scan revealed an oval-shaped cystic mass measuring 40×25×25 mm on the right side of the anterior mediastinum A teratoma was suspected because it had heterogeneous inner part with adipose component. Enbloc total resection of the mass under thoracoscopic surgery confirmed the diagnosis of carcinoid measuring 5×5 mm in size within the mature teratoma. She has exhibited a good clinical course for 2 years after tumor resection. Spontaneously occurred malignant component of mature teratoma is rarely diagnosed and its clinicopathological behavior is unknown, however, several reported cases showed unfavorable clinical courses resulting in local spread and metastasis despite of multidisciplinary therapy. Malignant transformation of mature teratoma can occur and is difficult to diagnose radiologically. Complete surgical resection and careful pathological evaluation are required to treat mediastinal germ cell tumors.

A 72-year-old man fell down a steep slope on a mountain and had a left 9-11 rib fracture with slight traumatic hemopneumothorax. The next morning, he vomited, and his blood pressure dropped. Computed tomography revealed an increase in hemothorax, and more than 2,000 ml of blood was drained from his left thoracic cavity. We performed emergency surgery and found a pinhole-sized bleeding point in the descending aorta. The aortic injury was thought to have been caused by a nearby rib fracture tip. After suturing, the bleeding hemodynamics stabilized. The patient was discharged 14 days after the injury. Hemothorax following chest trauma is commonly associated with intercostal artery damage caused by rib fractures. It is rare that the cause is aortic injury, as in this case. However, delayed treatment can lead to death. Therefore, in cases of hemothorax after chest trauma, especially after rib fracture of the left back, it is important to exclude aortic injury.

Leiomyosarcoma of the chest wall is a rare disease. Here, we report a case of a 16-cm leiomyosarcoma of the chest radically resected after preoperative chemotherapy. A 54-year-old man presented with a large mass on the left anterior chest. Percutaneous needle biopsy showed non-epithelial malignancy. On a preoperative CT scan and MRI images, the chest wall invasion was suspected. As the tumor poorly responded to the preoperative chemotherapy, an operation was performed. Since the chest wall invasion was visually inapparent during the operation, only tumor resection was performed. Considering the possibility for positive margin, we avoided a one-step approach to reconstruction, covered the defect with an artificial dermis and finished the operation. After negative margin was confirmed by histopathological examination, we performed reconstruction with pedicled latissimus dorsi musculocutaneous flap and split thickness skin graft. The histopathological diagnosis was leiomyosarcoma of the chest wall. About 50% of the tumor had degenerated and necrotized by the preoperative chemotherapy. Although another operation was needed for dorsi musculocutaneous flap and skin graft where partially failed to take, the wound was finally completely cured. He received adjuvant chemotherapy after discharge, and he is alive without any recurrence for 3 years and 5 months after the first operation.

Solitary fibrous tumor (SFT) is a relatively rare tumor derived from mesenchymal cells. We experienced a case of malignant SFT that increased rapidly in size 17 years after its initial detection. The case involved a 74-year-old man who had been detected to have a pleural nodule and an anterior mediastinal nodule 17 years earlier. He did not desire to receive therapy and had been followed until one year before when both lesions started to grow. Partial resection of the lung including the tumors was performed. Intraoperative findings showed that the pleural lesion was a tumor emerging from the lung parenchyma. Pathological analysis showed CD34 (+) spindle-shaped cells, nuclear atypia, mitotic figures, and high MIB-1 index. The diagnosis was malignant SFT arisen from the visceral pleura. The anterior mediastinal nodule was diagnosed as type A thymoma. The SFT in this case increased rapidly in size one year before the operation, and it was possible that the degree of malignancy might increase during the course. However, the diameter was relatively small and FDG accumulation was low. SFT is a slowly increasing tumor and the prognosis is often good, but 10-30% of them are malignant, and it is considered difficult to preoperatively distinguish between benign and malignant SFTs. Therefore, surgical resection may be considered when SFT is suspected.

A 59-year-old man presented for examination at our hospital after an abnormality was identified on an upper gastrointestinal contrast study during a health checkup. A type 2 tumor was present in the gastric cardia, with invasion of the abdominal esophagus. Cardiac gastric cancer at the esophagogastric junction was diagnosed, the abdominal esophagus was divided transhiatally, and total gastrectomy (with D2 lymph node dissection) was performed. Pathological analysis showed poorly differentiated adenocarcinoma and squamous cell carcinoma, and adenosquamous carcinoma was diagnosed. Adenocarcinoma and squamous cell carcinoma were both present together in a central collision zone, making this a collision-type tumor, a phenomenon that is particularly rare in adenosquamous carcinoma. Because marked lymph node metastasis was present, postoperative adjuvant chemotherapy with S-1 and CDDP was given, and, as of 6 years postoperatively, the patient is surviving recurrence-free. A case of collision-type gastric adenosquamous carcinoma at the esophagogastric junction is presented.

A 78-year-old man visited his local physician with a chief complaint of abdominal discomfort. Total serum protein and albumin levels were markedly decreased. Gastroscopy showed a circumferential type 1 tumor and a continuous extensive 0-IIa lesion at the mouth of the tumor in the gastric vestibule. Biopsy revealed papillary adenocarcinoma and highly differentiated adenocarcinoma. Preoperative computed tomography showed massive ascites and pleural effusion. A preoperative diagnosis of cT4a(SE)N+M0 or 1 and suspected stage III or IV disease was made. Distal gastrectomy (D2 lymph node dissection) and Roux-en-Y reconstruction were performed. A large amount of chylous ascites was found in the abdominal cavity, but the corresponding cytology was negative. The pathological diagnosis was pT1bN0M0, stage IA. Following surgery, the total serum protein and albumin levels improved over time. We encountered a case of early stage gastric cancer with protein loss, large volume ascites, and pleural effusion, which was incorrectly suspected to be advanced gastric cancer.

A 77-year-old man presented to our hospital complaining of neck discomfort. Upper gastrointestinal endoscopy showed early-stage gastric cancer in the greater curvature of the inferior gastric corpus, and endoscopic submucosal dissection was performed, but since the endoscopic curability was C2, additional resection was performed. Preoperative abdominal contrast-enhanced computed tomography (CT) showed that the left gastric vein was flowing into the umbilical portion of the portal vein, and the presence of a left portal vein was diagnosed. A left accessory hepatic artery branching off the left gastric artery was also observed, as was abnormal development of the collateral circurations of the head of the pancreas as a result of celiac axis occlusion. Laparoscopic distal gastrectomy and D1+ lymph node dissection were performed. In this operation, care was taken to avoid damaging the anterior superior pancreaticoduodenal artery, and the left accessory hepatic artery was preserved to prevent reduced hepatic perfusion postoperatively. The left gastric vein ran alongside the left accessory hepatic artery within the hepatogastric ligament, and it was divided near the left accessory hepatic artery bifurcation. Although liver enzymes were mildly elevated postoperatively, the patient's course was otherwise uneventful. This surgical patient who showed noteworthy vascular branching and morphological abnormalities, in addition to an extremely rare left portal vein, is presented.

A 62-year-old man underwent distal partial gastrectomy for advanced gastric cancer (sig, por, T4aN1M0, Stage IIIA). The patient was given adjuvant chemotherapy consisting of 6 courses of capecitabine plus oxaliplatin. Nine months after the initial operation, two metastatic abdominal wall tumors were found on the operation scar. The tumors were removed surgically, and the abdominal wall defect was reconstructed with mesh. Nine months after removal of the abdominal tumors, new metastatic tumors appeared in the lower right abdominal wall. Three months later, metastatic tumors appeared in the gluteal muscles and the skin of the whole body. The patient was treated with 2 courses of a weekly paclitaxel regimen. However, each tumor grew, so the chemotherapy was interrupted, and he was changed to palliative therapy. He died of progressive disease 17 months after resection of the abdominal wall tumors. We report a case of abdominal wall metastasis resection of gastric cancer, in which the patient lived without any cancer recurrence for 9 months after operation, but then developed systemic soft tissue metastasis and died. This case highlights the need to think about the treatment plan for abdominal wall metastases of gastric cancer and attempt to predict the clinical course after their resection.

A 78-year-old man presented with dyspnea on exertion. An upper gastrointestinal endoscopy showed irregular shaped lesions in the upper, middle, and lower gastric body. A lower gastrointestinal endoscopy showed an ulcerative tumor in the rectum. We diagnosed the case as simultaneous multiple gastric carcinoma (cT2N0M0, cStage I) and rectal carcinoma (cT2N0M0, cStage I), and performed total gastrectomy and anterior resection of the rectum. Macroscopic image of the gastric specimen showed three lesions : (a) type 2 tumor 35 mm in longer diameter in the upper stomach, (b) type 1 tumor 30 mm in longer diameter in the middle stomach, and (c) type 0-IIc tumor 5 mm in longer diameter in the lower stomach. Histopathological examination revealed that the three lesions were (a) mixed adenoneuroendocrine carcinoma (MANEC) (poorly-differentiated adenocarcinoma and neuroendocrine carcinoma), pT2, (b) well-differentiated tubular adenocarcinoma, pT1a, and (c) moderately-differentiated adenocarcinoma, pT1a, respectively. This case was diagnosed as simultaneous triple gastric cancers including a MiNEN (MANEC). Although MANEC is a rare malignant tumor, there are various potential histogenesis. In this case, MANEC appeared as one of multiple gastric adenocarcinomas and NEC existed as it was surrounded by adenocarcinoma tissue. Adenocarcinoma might transform into endocrine component. The coexistence of a rectal cancer suggests abnormalities in mismatch repair genes.

A 56-year-old woman was admitted to our hospital for close exploration for persistent epigastralgia and vomiting. On admission, blood tests revealed no abnormalities. An abdominal ultrasonography showed a 28-mm cystic lesion in the vicinity of the pyloric ring. Upper gastrointestinal endoscopy revealed a finding such that the tumor projected from the gastric cavity into the duodenum and almost completely occluded the duodenal bulb. A biopsy gave no malignant findings. An abdominal contrast-enhanced CT scan conducted on the second hospital day showed a slightly shrinking tumor. On the additional endoscopy conducted on the fourth hospital day, the tumor was present in the duodenal bulb, but it was depressed and reduced in size, and the occlusion was already released. Esophagogastroduodenoscopy on the nineth hospital day showed an expanding translucency in the duodenal bulb. Although no definite diagnosis was made, we performed distal gastrectomy for fear that duodenal occlusion would recur. We also confirmed from the surgical specimen that the tumor had expanded and enlarged again. The histopathological diagnosis was Brunner's gland cyst. As occlusion of the duodenal bulb with the Brunner's gland cyst is rare, we present our case with some bibliographic comments.

Herein, we report a case of acute appendicitis during pregnancy that was treated with laparoscopic interval appendectomy after emergent percutaneous abscess drainage. A 35-year-old woman in the twelfth week of pregnancy was admitted to our hospital complaining of right lower abdominal pain. Ultrasound and MRI scans revealed a 5-cm fluid and gas collection in the retrocecal area, and abscess formation was diagnosed as acute appendicitis. Percutaneous abscess drainage was performed with sufficient effort to reduce fetal radiation exposure, and continuous drainage shrunk the collection significantly. Laparoscopic appendectomy was performed 33 days after the first admission. The postoperative course, pregnancy course, and fetal development were uneventful. The patient was discharged on day 6, and she delivered a healthy boy weighing 2880 g in the 41st week without complications. To our knowledge, this is the first report of laparoscopic interval appendectomy via percutaneous abscess drainage for acute appendicitis during pregnancy.

Case 1 involved a 73-year-old man who presented to our hospital for right lower quadrant pain. He was diagnosed as having acute appendicitis with an abscess and underwent an appendectomy two days after conservative treatment. Histopathological examination revealed appendiceal diverticulitis, goblet cell adenocarcinoma (GCA) and positive resection margin. He refused to undergo any additional ileocecal resection. Thirty-four months later, he died of lung metastases and carcinomatous peritonitis. Case 2 involved a 39-year-old man who presented to our hospital for right lower quadrant pain. He was diagnosed as having acute appendicitis and received conservative treatment using oral antibiotics. One day later, because of aggravated symptoms, appendectomy was performed. Multiple diverticula and localized wall thickening were found in the resected specimens. Histopathological examination revealed GCA invading the subserosal layer. Additional laparoscopic ileocecal resection was performed two months later. There was no residual GCA in the resected specimen (pT3N0M0, Stage II). Adjuvant chemotherapy (4 courses with XELOX) was performed, and he has had no signs of recurrence 11 months after the operation. Because appendiceal diverticula can be associated with appendiceal tumors, including mucinous neoplasms and GCA, careful image diagnosis and pathological examination should be performed for patients with acute appendicitis.

A 78-year-old woman was admitted to our hospital with impaired consciousness. She presented with septic shock, and blood examinations showed an increased inflammatory response and hepatorenal dysfunction. Contrast-enhanced computed tomography (CT) showed edematous wall thickening and poor contrast enhancement in the lower small intestine. Three-dimensional CT angiography revealed non-visualization of the marginal artery of the small intestine, which led to the diagnosis of non-occlusive mesenteric ischemia (NOMI). Eighteen hours after admission to the intensive care unit (ICU), a blood test showed deterioration of inflammatory reactions and hepatorenal dysfunction, strongly suggesting intestinal necrosis. Ultrasonography (US) showed wall thickening and emphysema in the lower small intestine ; however, color Doppler US showed a pulsatile blood flow signal in those intestines, which led us to continue conservative treatment. Subsequent US showed a pulsatile blood flow signal in the small bowel and reduced intramural emphysema. The patient was discharged from the ICU 8 days after admission and was discharged to her home after 37 days of hospitalization. In this case, US was useful for determining the treatment strategy for NOMI.

A 74-year-old man presented with abdominal pain. He was diagnosed with superior mesenteric venous thrombosis (SMVT) accompanied by small bowel necrosis with a contrast-enhanced CT scan and underwent an emergency operation. Although we performed resection and anastomosis of the necrotic site, impaired blood flow at the anastomosed intestine was confirmed during the operation and additional bowel resection and re-anastomosis were conducted. A small intestine, totally 70 cm in length, was resected. A blood analysis indicated that coagulation abnormality was unlikely. As a previous upper gastrointestinal endoscopy detected esophageal varices, it was considered that SMVT had been formed due to portal hypertension. After the operation, anticoagulation therapy with low-molecular-weight heparin was started. The thrombosis started to shrink during hospital stay, he was discharged from our hospital on 22^nd postoperative day, and the thrombosis disappeared in 3 months after the operation. He has been free from recurrence up to now and is under anticoagulation therapy in our clinic.

We have reviewed a total of 30 domestic cases of SMVT + small bowel necrosis including our case in terms of the election of one- or two-step approach for surgery and anticoagulation therapy.

The patient was an 80-year-old man who was brought to the emergency room with a complaint of abdominal pain. The patient had idiopathic thrombocytopenic purpura (ITP) and was taking eltrombopag 50 mg. Computed tomography showed thrombi in the portal vein (PV) and superior mesenteric vein (SMV), ascites, and poor contrast of the small bowel wall. He was therefore diagnosed with small bowel necrosis due to PV/SMV thrombosis. His platelet count was low at 20,000/μl, and the patient underwent emergency surgery with platelet transfusion. Intraoperative findings showed necrosis of 150 cm of the small intestine, and therefore resection of the whole necrotic small intestine was performed. Anticoagulant therapy was started after the surgery, but the platelet count tended to decrease, and there was concern about the risk of bleeding. Thus, the patient underwent splenectomy on the 13th day of hospitalization ; the platelet count increased immediately after the second surgery. On the 24th day of hospitalization, abdominal CT showed that the thrombi had shrunk, and the patient was discharged on the 38th day of hospitalization. Eltrombopag has been reported to cause PV/SMV thrombosis ; therefore, if a patient taking eltrombopag complains of abdominal pain, PV/SMV thrombosis should be considered.

A 67-year-old man was undergoing postoperative follow-up for two colorectal cancers. Laparoscopic partial resection of the small intestine and excisional biopsy of the mesenteric lymph node of the small intestine were performed after neoplastic lesions of the small intestine with distant lymph node metastasis were diagnosed by CT and FDG-PET in August 2017. The pathological diagnosis was primary small intestinal cancer with lymph node metastases. After the operation, chemotherapy with anti-EGFR antibody was started for the remaining mesenteric lymph node and distant lymph node metastases, and the distant lymph nodes shrank, resulting in a complete response. Screening for Lynch syndrome was performed, and a germline gene examination showed a pathogenic variant in the MSH2 gene, which was diagnosed as Lynch syndrome. Systemic chemotherapy was then continued, and the complete response was maintained. However, the treatment was discontinued in December 2018 at the patient's request. In February 2019, the patient was diagnosed with bladder cancer and chemotherapy for it was started, but the bladder cancer was refractory to it. In July of the same year, treatment with pembrolizumab was started at our hospital. The bladder cancer progressed, and the patient finally died a year later.

A 36-year-old man, who was brought into a hospital for left-sided abdominal pain during a business trip abroad, was diagnosed with superior mesenteric artery occlusion of unknown cause and came home after medical treatment. His abdominal pain was persistent and he presented to our hospital. Abdominal contrast-enhanced CT scan showed dissection of the superior mesenteric artery, an aneurysm of the left colic artery and a surrounding hematoma. Angiography of the inferior mesenteric artery showed an aneurysm and irregular dilatation of the marginal artery at the splenic flexure. Transcatheter arterial embolism (TAE) was not performed because there was a high possibility of intestinal ischemia. We decided to perform semi-urgent laparoscopic left hemicolectomy. Operative findings included intraabdominal hemorrhage and extensive hematoma in the vicinity of the splenic flexure. The colon was divided from the retroperitoneum under laparoscopy. The vascular ligation was performed from a small laparotomy. The pathological diagnosis was segmental arterial mediolysis (SAM). We treated conservatively for the superior mesenteric arterial aneurysm, and one month later thrombosis of false lumen was formed. We report our experience with a case of laparoscopic assisted surgery for a ruptured left colonic artery aneurysm caused by SAM.

In laparoscopic surgery for descending colon cancer with a concurrent abdominal aortic aneurysm (AAA), attention must be paid to the mobilization of the colon and to perfusion through the anastomosis. An 83-year-old man was diagnosed with descending colon cancer (cT3N0M0 : cStage IIa), and surgery was scheduled, but preoperative computed tomography showed a saccular AAA with a diameter of 51 mm. It was therefore decided to perform the surgery in two stages. Stent graft insertion (endovascular aneurysm repair, EVAR) was performed first, with laparoscopic colectomy carried out one month later. To avoid damaging the AAA, the medial approach was not used ; the left colon was mobilized from the lateral and cranial sides, and resection and reconstruction were performed via a small abdominal incision. Given the perfusion through the anastomosis, only D1 lymph node dissection was performed. There were no major complications, and the patient was discharged on postoperative Day 14. The case of a patient in whom AAA and descending colon cancer were discovered simultaneously, who was treated by two-stage surgery consisting of EVAR and subsequent laparoscopic colectomy, is presented. It was possible to avoid intraoperative damage and suture failure by being careful of the AAA during colon mobilization and deciding on the extent of resection in light of changes in perfusion associated with post-EVAR inferior mesenteric artery occlusion.

A 61-year-old man with sigmoid colon cancer and multiple liver metastases (KRAS wild type) was treated with resections of the sigmoid colon and a part of the liver, followed by chemotherapy with FOLFIRI or IRIS therapy in combination with panitumumab (Pmab) for 15 months. After an imaging CR and drug withdrawal, liver metastases reappeared 6 months later. Pmab/IRIS or Pmab/FOLFIRI therapy was resumed, and 7 months later partial hepatectomy was performed. Four months after the second surgery, metastases appeared near the IVC in the liver S7. Chemotherapy with SOX, FOLFIRI, or ISIS therapy in combination with Pmab was performed, that was effective for 2 years and 3 months. Afterwards, the tumor had come to grow rapidly, so resection of the liver combined with parts of the IVC wall was performed. Five months later, solitary lung metastasis appeared and was resected. Further two months later, multiple metastases to the lungs, bone, and adrenal glands appeared. Then, we tried to rechallenge Pmab alone chemotherapy, resulting in marked shrinkage of the metastases. The patient has been treated with Pmab alone for 2 years and 10 months with gradually increasing intervals and is still alive and well 9 years after the initial diagnosis. We present a patient with sigmoid colon cancer with liver metastases who survives for 9 years with aggressive resection and Pmab rechallenge.

A case of hepatocellular carcinoma in a patient with Dubin-Johnson syndrome (DJS) focusing on evaluation of hepatic functional reserve and the perioperative clinical course is presented.

A 66-year-old man with a medical history of DJS and diabetes mellitus was diagnosed with hepatocellular carcinoma (HCC) when he had a rickettsial infection. The preoperative liver function tests showed an increased bilirubin level (total 4.6, direct 3.4 mg/dl), and normal PT (92%) and albumin (4.2 g/dl) levels without ascites or encephalopathy. The Child-Pugh score was B (7). The ICGR₁₅ level was 11%. The LHL₁₅ value of the GSA scintigram was almost normal (0.909). S4 segmentectomy and S2 partial resection were performed uneventfully except for transient elevation of the T-Bil level that recovered to the preoperative level on the 28^th postoperative day. DJS was confirmed on histopathological examination. Both the ICG test and the GSA scintigram evaluated hepatic functional reserve accurately. Inchin-ko-to may be effective for hyperbilirubinemia after hepatectomy in DJS cases.

An 87-year-old man underwent right posterior sectionectomy for ruptured hepatocellular carcinoma (HCC) in segment 6 of the liver ; the pathological diagnosis was moderately-differentiated HCC with microvascular invasion. A small nodule was detected on the cut end of the remnant liver 16 months after surgery. The size of the nodule rapidly increased from 1 cm to 5 cm over a period of 5 months. He was therefore referred to our hospital where he underwent partial hepatectomy.

The tumor had a capsule protruding from the caudal side of the liver, and no disseminated nodules were detected. A dilated vein with a diameter of 5 mm extending from the tumor was detected and radically resected. The tumor was histopathologically diagnosed as a poorly-differentiated HCC with tumor thrombi in the omental vein. HCCs rarely form tumor thrombi in systemic veins other than the portal vein and hepatic veins ; hence, accurate preoperative diagnosis and appropriate surgical management are required in such cases.

A 71-year-old man presented in our clinic with a chief complaint of back and orbital pain. Previous computed tomography performed at a doctor's clinic revealed cholelithiasis and a papillary tumor in an enlarged gallbladder with mild bile duct dilatation extending from Vater's papilla to the intrahepatic bile ducts. Five days later, he returned to the emergency room due to worsening of right-sided back pain. He was admitted with obstructive jaundice and acute cholangitis. Endoscopic retrograde cholangiopancreatography was performed, and an endoscopic nasobiliary drainage tube was placed. Excessive mucus secretion quickly led to tube dysfunction, and daily saline lavage was necessary to maintain biliary drainage. He was diagnosed with intracholecystic papillary neoplasm (ICPN) from a papillary tumor in the gallbladder with mucus discharge from Vater's papilla. Complete cholecystectomy was then performed, and histopathological diagnosis showed biliary- or oncocytic-type ICPN.

We report a rare case of mucus-associated obstructive cholangitis in a patient with ICPN.

A 60-year-old woman who had locally advanced borderline resectable pancreatic cancer associated with extensive portal vein invasion was determined not to be a candidate for reconstruction of portal veins. Consequently, she underwent 12 cycles of gemcitabine+nab-paclitaxel therapy followed by 23 cycles of gemcitabine therapy. In an early time after initiation of the chemotherapy, abnormally high tumor marker levels were normalized and the size of the primary tumor was significantly reduced. Since the primary tumor had become obscure and the tumor marker levels were kept within normal ranges for a long time, she underwent subtotal stomach-preserving pancreatic duodenectomy. Histopathological findings revealed fibrosis covering a wide range of the specimen and absence of tumor cells, and she was diagnosed to have achieved pathological complete response. She received adjuvant chemotherapy with S-1 monotherapy for 6 months, and she has been alive without recurrence as of 8 months after the operation.

Background : The arterial supply to the splenic flexure of the colon derived from the left aspect of the superior mesenteric artery (SMA) is called accessory middle colic artery (accMCA). This variation has been reported in 34% of the population. However, few reports have described the anatomical variation of an accMCA originating from the splenic artery (SA).

Case presentation : A 71-year-old man with a complaint of appetite loss was referred to our hospital. Contrast-enhanced computed tomography (CT) scan revealed a hypovascular mass in the body of the pancreas. Additionally, an accMCA originating from the root of the SA was detected using 3D-CT reconstruction images, which also revealed that the tumor had invaded the accMCA and spleno-mesenteric confluence. The tumor abutment of the SMA and SA involved <180° of the circumference of the artery. Neoadjuvant therapy was initiated, followed by distal pancreatectomy with concomitant accMCA resection and wedge resection of the superior mesenteric vein. Postoperatively, the adequacy of blood flow to the colon was confirmed by indocyanine green fluorescence imaging. The patient's postoperative course was uneventful, and he was discharged on postoperative day 15.

Conclusion : An accMCA arising from the SA without the left branch of the MCA is very rare. We preoperatively diagnosed this variation using 3D-CT, and concomitant resection was safely performed with distal pancreatectomy for pancreatic cancer.

A 65-year-old woman underwent laparoscopic right nephrectomy for renal cell carcinoma (RCC). Nine years after the operation, abdominal computed tomography (CT) showed a 10-mm tumor in the pancreatic body, which was diagnosed as pancreatic metastasis of RCC. Considering that it was a single metastasis, laparoscopic enucleation of the pancreatic metastasis was performed, and the pathological diagnosis was pancreatic metastasis of RCC. The patient's postoperative course was uneventful, and she was discharged from the hospital 9 days after the operation. Six months after the pancreatectomy, abdominal CT showed two tumors in the pancreatic body, and the patient was diagnosed with recurrent pancreatic metastases. Considering multiple recurrence in the early postoperative period, a molecular-targeted drug was administered ; however, the drug was discontinued after 3 months due to side effects. Twelve months after the discontinuation of the drug, no new tumor appeared. However, laparoscopic distal pancreatectomy was performed because the old tumors increased in size. No recurrence was observed 1 year after the second pancreatectomy. In pancreatic metastasis of RCC, it is necessary to have a treatment strategy aiming at both preservation of function and long-term survival, keeping in mind the possibility of potential metastatic lesions.

A 53-year-old woman presented with sudden onset of abdominal pain and vomiting. She had no history of abdominal surgery. Enhanced abdominal computed tomography showed ascites and poorly enhanced small intestine in the pelvis along the dorsal side of the left fallopian tube. Strangulated bowel obstruction with intestinal necrosis due to an incarcerated internal hernia through the broad ligament was diagnosed. Emergency open laparotomy was performed 18 hours after onset of symptoms. Massive serous ascites was found. The ileum passed through a defect in the left side of the broad ligament and was easily reduced. The color of the small intestine recovered after 15 minutes. There was a lipoma-like mass on the incarcerated intestinal wall suspected to be the lead point causing incarceration of the ileum. Resection of a 20-cm portion of dusky ileum along with this mass was performed, and the hernia opening was closed. Clostridium difficile enteritis developed postoperatively, the patient recovered uneventfully, and she was discharged on postoperative day 10. Pathological diagnosis was ectopic pancreas in the ileum. This is the first patient with an incarcerated internal hernia through a defect in the broad ligament of the uterus caused by an ectopic pancreas in the ileum in Japan.

We report our experience with a case of plasmacytoid variant of bladder cancer in which bowel obstruction due to peritoneal dissemination was the initial symptom.

A 75-year-old male patient presented with abdominal pain. An abdominal CT scan showed a colonic dilatation with an obstructive origin in the transverse colon, which was thought to be primary in the stomach or transverse colon. Since the tumor was unresectable, we performed a palliative bypass between the ileum and transverse colon followed by chemotherapy. The patient responded temporarily, but his condition worsened, and an additional upper and lower gastrointestinal endoscopy demonstrated no obvious neoplastic lesion. An additional abdominal CT scan revealed a thickened bladder biome, and so a cystoscopy was performed. Although there was no obvious invasive carcinoma in the bladder mucosa, transurethral resection of the same area confirmed the diagnosis of plasmacytoid variant bladder cancer. His condition deteriorated rapidly, and palliative care was decided. He died at a hospital to where he was transferred.

In the diagnosis and treatment of malignant tumors, we should make efforts to add findings and examinations from other fields. Even when peritoneal dissemination precedes and intestinal obstruction was the first symptom, it is important not to assume that gastrointestinal cancer should be the primary tumor, but to also differentiate between bladder cancer and plasmacytoid variant bladder cancer as in this case.

Peritoneal dialysis-related peritonitis is one of the most serious complications that can occur in patients undergoing peritoneal dialysis. We report our experience with laparoscopic catheter removal and peritoneal lavage in two cases of peritoneal dialysis-related peritonitis. Case 1 : A 68-year-old man, who had been on peritoneal dialysis for 4 years, was admitted to the hospital with peritoneal dialysis-related peritonitis. Candida albicans was detected in the waste fluid culture, and fungal peritonitis was diagnosed. Case 2 : A 44-year-old man who had been on peritoneal dialysis for 3 months developed peritoneal dialysis-related peritonitis secondary to outlet infection. After 5 days of antibiotic therapy, he continued to have fever and cloudy peritoneal effluent and was diagnosed with refractory peritonitis. In these two cases, we removed the catheters and then performed abdominal lavage via laparoscopy until there was no cloudiness in the lavage fluid. No postoperative complications were observed. Early catheter removal combined with peritoneal lavage drainage will contribute to the safe treatment of peritoneal dialysis-related peritonitis.

A 77-year-old woman who had received sigmoidectomy for sigmoid colon cancer in 2017 was incidentally found having a round tumor in the presacral space with a follow up pelvic computed tomography. A preoperative diagnosis of presacral liposarcoma was made because it tended to enlarge gradually, and we resected the presacral tumor by robotic surgery. The tumor was found to have invaded the presacral space, and the boundary with the mesenteric fat was slightly unclear. Microscopically, the adipose tissue and bone marrow elements, megakaryocytes, normoblasts and myelocytic cells, were noted. The tumor was diagnosed as myelolipoma. Myelolipoma is a benign tumor which is usually found in the adrenal gland and rarely in the extraadrenal areas. In this case, it was difficult to identify the boundary between the tumor mainly composed of fat and the mesenteric fat. We experienced a case of presacral myelolipoma in which stable, high-resolution 3D images and highly flexible, articulated surgical instrument enlargement were useful. This is the first case of robotic surgery for presacral myelolipoma.