Purpose : Patients who develop pulmonary thromboembolism following gastrointestinal cancer surgery often have a poor outcome, and the early diagnosis and prevention of deep vein thrombosis (DVT), which is a potential cause of pulmonary thromboembolism, are therefore important. Methods : Of 423 patients who underwent elective surgery for abdominal gastrointestinal cancer between June 2014 and March 2021, a retrospective investigation of perioperative DVT risk factors was conducted by reviewing the patients' characteristics and surgical factors in 228 patients who underwent preoperative venous ultrasound of the legs and 132 who underwent postoperative venous ultrasound of the legs because their postoperative D-dimer level was ≥10.0 μg/mL. Results : DVT was observed in 2.2% of the preoperative and 7.5% of the postoperative patients. Hemoglobin <10 g/dL was identified as a risk factor for preoperative DVT, and body mass index ≥30 kg/m² and intraoperative hemorrhage ≥500 mL were identified as risk factors for postoperative DVT. Conclusions : More evidence concerning perioperative DVT in Japanese patients is needed to establish a risk-score-based classification and determine the need for anticoagulant therapy.

A 35-year-old woman noted bloody discharge in her left nipple in the second month of the lactation. Three months later, a mass was observed in the left breast ; however, no hospital consults were carried out. During the eighth month of lactation, the persistence of the intermittent left nipple bloody discharge prompted a consult to our institution. She presented with a 70 mm mass around the A segment of her left breast. Mammography revealed a linear calcification in the segment, and contrast magnetic resonance imaging revealed segmentary non-mass enhancement. She was diagnosed with ductal carcinoma in situ in her left breast by core needle biopsy, with elevated levels of CEA and serum HER2. Positron emission tomography showed no apparent distant metastasis, lymph node metastasis, or tumor of other organs. Left mastectomy and sentinel lymph node biopsy were performed. The patient's high tumor marker levels were found to be due to breast cancer, which explained the rapid decrease of the tumor marker levels following the left breast mastectomy. The frequency of elevated tumor marker levels in early breast cancer is rare. In this case, we deduced that lactating breasts and extensive intraductal development contributed to elevated tumor marker levels.

A 79-year-old woman presented with a mass in the two o'clock position of her left breast. She had a history of right mastectomy for right breast cancer 20 years ago and pacemaker (PM) implantation for arrhythmia 16 years ago. Physical examination revealed induration not only in the 2 o'clock direction but also directly above the implanted PM. A needle biopsy of the mass revealed invasive ductal carcinoma of the breast. Fluorodeoxyglucose-positron emission tomography showed a strong accumulation in the mass directly above the PM, as well as in the main mass, suggesting multiple breast cancers on the same side of the PM. After conversion to leadless PM, a left total mastectomy and axillary lymph node dissection were performed, with PM resection. Pathological examination confirmed that the mass just above the PM was also an independent invasive carcinoma. The tumor's resection margins were negative. Herein, we have reported the diagnosis and treatment of PM-associated breast cancer, with a literature review.

We present the case of a woman with Cowden syndrome who developed breast cancer. A 37-year-old woman presented with a thyroid adenoma, identified during a follow-up computed tomography scan for her pharyngeal mucosal polyposis. Due to the presence of macrocephaly and a skin tumor in her lower jaw were also observed, she was suspected of having Cowden syndrome. Her right breast cancer was also diagnosed via mammography, ultrasonography, and core needle biopsy, and was managed via mastectomy. Gene testing identified a pathogenic germline mutation of the PTEN gene.

We report a case of retroperitoneal metastasis of invasive ductal breast carcinoma. A 62-year-old woman underwent surveillance computed tomography (CT) one year post-mastectomy. CT revealed bilateral hydronephrosis, for which bilateral ureteral stents were placed. The patient also noted the development of nausea and lower extremity edema. CT and upper gastrointestinal examinations revealed severe stenosis of the duodenum and the inferior vena cava, without a space-occupying lesion in the retroperitoneum. She underwent a gastro-jejunostomy with biopsy of the retroperitoneal tissue, for a suspected recurrence of her breast cancer. Histological examination of retroperitoneal tissue revealed breast cancer metastasis. Though chemotherapy was planned, she was diagnosed with meningeal carcinomatosis 1 month later, after presenting with severe headaches. The patient died 2 months after the laparotomy. Despite the rarity of retroperitoneal breast cancer metastasis, it should be considered for patients with a history of breast cancer.

We report a case of an oligometastatic pulmonary tumor from breast cancer treated using proton beam therapy. A 48-year-old female underwent a partial mastectomy to manage her triple-negative breast cancer 6 years ago. Approximately 3 years postoperatively, she was diagnosed with a solitary pulmonary metastasis from her breast cancer. The lung tumor increased in size despite two courses of S-1 administration. She received proton beam therapy at another radiation facility with a total dose of 66 Gy in ten fractions. The tumor disappeared 3 months after treatment, and she remained in complete remission for 2 years, without the need for adjuvant therapy. The acute side effects experienced by the patient included grade 1 pneumonitis and grade 1 dermatitis, according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0. No late complications were observed.

A 73-year-old woman presented to our hospital with an abnormal shadow on her chest computed tomography (CT). It showed a 2.5 cm nodule in the anterior mediastinum. On dynamic contrast-enhanced CT (dynamic CT), peripheral puddles were found in the nodule. Enhanced magnetic resonance imaging (MRI) also showed peripheral enhancement ; low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. There were no findings invading the surroundings directly. Surgery was performed under the suspected diagnosis of mediastinal hemangioma. The histopathological diagnosis was cavernous hemangioma. Mediastinal hemangioma is a rare entity, and it is difficult to make the diagnosis preoperatively with imaging studies. In this case, the combined use of dynamic CT and MRI was useful to make the preoperative diagnosis of mediastinal hemangioma and to remove it safely by thoracoscopic surgery.

A 68-year-old man was referred to our hospital because of a 6 × 7 mm nodule in the upper lobe of the right lung and multiply accumulated nodules in the bilateral posterior mediastinum on CT scan performed before surgery for prostatic cancer. Metastatic lung cancer and mediastinal tumors including fatty components were suspected. We performed thoracoscopic partial resection of the lung and a biopsy of the mediastinal tumor ; the pulmonary nodule was resected by using a stapling device with a sufficient distance from the nodule. An intraoperative frozen section examination reported a suspicious nodule to be metastatic lung cancer from prostatic cancer. The mediastinal tumors were confirmed as dark red nodules ridging in the thoracic cavity from the outside of the parietal pleura. Incision of the pleura with an electric scalpel disclosed the lesion to be red, gelatinous and easily hemorrhagic tissue. We collected a portion of the tissue to send it to the Pathological Department. As a result of histopathological examination of the permanent preparation, the pulmonary nodule was diagnosed as primary lung cancer and the mediastinal tumors, as myelolipoma. We present this case with some bibliographical comments, because myelolipoma arising multiply in the bilateral posterior mediastinum is very rare.

A 56-year-old man was referred to our hospital due to left acute pleural empyema. Computed tomography scans revealed left massive pleural effusion and atelectasis of the left lower lobe with obstruction of the left lower bronchus and circular calcification of the bronchial wall. Bronchoscopy revealed obstruction of the ostium of the left lower bronchus by granulomatous tissue. Histopathological examination did not identify any malignancy or significant bacillus. His acute pleural empyema improved following reduction in inflammation indices after video-assisted thoracoscopic pleural decortication. Follow-up bronchoscopy detected decreasing granulation tissue of the bronchial mucosa and a cylindrical foreign body in the left lower bronchus. The patient underwent tracheal intubation with deep sedation for extraction of the foreign body by bronchoscopy. Single forceps via an operation channel of the bronchoscope failed to extract the foreign body. Additional forceps were inserted alongside the bronchoscope so opposite sides of the foreign body could be grasped simultaneously and gently extracted without damaging the surrounding tissue. The foreign body was a plastic pencil cap the patient had aspirated accidentally when playing in a swimming pool at nine years of age. We safely and successfully removed the 47-year lasting bronchial foreign body using flexible bronchoscopy.

Chylothorax is a common complication of thoracic surgery for lung cancer. It occurs after surgery for lung cancer and accounts for 1.2% - 3.0% of all complications. Generally, fasting, total parenteral nutrition (TPN), and thoracic duct ligation are the main treatments. Recently, it has been reported that lymphangiography is effective for postoperative chylothorax. We encountered a case, where lymphangiography was effective for chylothorax after lobectomy, which did not respond to thoracic duct ligation. A 40-year-old woman was diagnosed with lung cancer (cT4N0M0 : cStage IIIA), and underwent left upper lobectomy with phrenic and vagus nerve resection. On the second day following the operation, an infiltrative shadow was observed in the total left lung field. Drainage fluid from the chest tube appeared cloudy ; chylothorax was diagnosed and treatment for this complication was initiated on the third day. However, conservative treatment and thoracic duct ligation could not resolve the chylothorax, and lymphangiography by inguinal lymph node puncture was administered on the 30th postoperative day. On the next day, the drainage fluid appeared serous and chylothorax was resolved. Lymphangiography is considered effective for chylothorax resistant to conservative and surgical treatments, though it can be done in limited institutions.

A 64-year-old man underwent computed tomography (CT) because of discomfort in his anterior chest, and he was found to have a subdiaphragmatic tumor. Chest CT showed a 25 mm-sized subdiaphragmatic soft-tissue tumor with clear borders, and magnetic resonance imaging and positron emission tomography CT did not provide a definitive diagnosis. Considering a possibility of malignancy, we decided to perform a laparoscopic tumor resection. The tumor was located in the vicinity of the falciform ligament of the liver under the left diaphragm and could be resected without damaging the capsule. Postoperative histopathological examination revealed a cyst with a lumen lined by pseudostratified ciliated epithelium, and the cyst wall had smooth muscle layers through connective fibers. Based on the above, we diagnosed this mass as a bronchogenic cyst. Bronchogenic cyst is a congenital cyst of prenatal foregut origin, and the occurrence in the abdominal region is extremely rare.

A 42-year-old woman who presented with a slow-growing nodular lesion of 10.3 mm in diameter in the left lower lobe of the lung on CT taken for cervical cancer in 2013 was referred to our department in 2021 when the lung lesion increased to 14.8 mm. Although the nodule which had been diagnosed as benign was growing very gradually, the malignant disease including metastatic tumor could not be excluded. Thus, the resection of the tumor was carried out. The lesion was located near the left inferior pulmonary vein enough to indicate the lower lobectomy of the lung. However, by transecting the V10 branch, the lesion was successfully removed by wedge resection with a stapler with a surgical margin of about 5 mm from the inferior pulmonary vein. Intraoperative frozen sectioning disclosed possible pulmonary sclerosing pneumocytoma or adenocarcinoma in situ without any findings of invasiveness. Thus, further extended resection was not carried out by securing 5 mm surgical margin. The postoperative pathological diagnosis defined pulmonary sclerosing pneumocytoma. The patient is well without recurrent disease as of 12 months after the surgery.

Palpation of the lesions is challenging during lung resection for small, deep-seated and ground glass opacity nodules, which often require preoperative localization marking. Radiofrequency identification (RFID), a digital marking technology using a bronchoscope, has clinically been applied in recent years. RFID marking accurately localizes even deep-seated lesions, however, little is known about its complications. Here, we report intraoperative displacement of the tag placed from the airway for the first time. A 71-year-old woman with suspected metastatic lung cancer (an 8-mm nodular shadow in the S10 of the left lung) underwent thoracoscopic wedge resection after RFID-based localization at two sites. We experienced RFID tag displacement in one out of the two tags requiring a wider wedge resection during the surgery than scheduled. The displacement might be caused by shaft wire distortion secondary to gripping with the ring forceps and extrusion with multiple clamping by the endo-staplers during lung resection. Manipulation using ring forceps or multiple clamping by endo-staplers should be avoided in the vicinity of RFID tags during lung resection. A RFID tag should be placed in the peripheral airway near the lesion.

It is known that cerebral infarction after lung resection is mainly caused by thrombus formation at the surgical stump of the pulmonary vein. A 86-year-old man was diagnosed with left upper lobe lung cancer + left lower lobe lung cancer and was scheduled to undergo passive partial resection of the left upper lobe + S6 segmentectomy. We performed partial resection of the left upper lobe, followed by S6 segmentectomy to treat V6, A6, and B6. However, intraoperative findings determined that S6 segmentectomy was insufficient, and then we converted the operative procedure to left lower lobectomy. The common basal vein was transected at a slightly peripheral site not to involve the V6 stump staple where was precedingly resected ; the basal segmental artery and basal branch were transected to complete left lower lobectomy. On the next day, left hemiplegia suddenly occurred. Following MRI, we diagnosed his illness as postoperative right middle cerebral artery territory infarction. Percutaneous thrombectomy was performed. A chest CT scan confirmed a left lower pulmonary vein stump to be as long as 2.8 cm. Other risk factors causing cerebral infarction could be ruled out with close examinations. We consider that the treatment of the common basal vein at the periphery of V6 staple at the conversion of surgical procedure made the pulmonary vein stump longer and the resultantly formed vein stump thrombus caused cerebral infarction.

A 66-year-old woman was referred to our hospital because a hepatic mass was newly detected through abdominal US executed routinely every year. Abdominal CT showed a 40-mm low density area with slight contrast effects in the segment 6 of the liver. Tumor markers were within normal ranges. CT also showed a solitary nodule of 8 mm in diameter in the segment 8 of the right lung, which was to be observed because of its size and unknown origin. On the other hand, the liver tumor was to be resected because of its rapid growth implicating a malignant potential. Histologically, the liver tumor was composed of proliferation of spindle-shaped atypical cells with a high NC ratio. Immunostaining revealed that the tumor cells were both chromogranin-A and synaptophysin positive, which indicated the tumor to be neuroendocrine origin. Thyroid transcription factor (TTF)-1 was also positive which suggested the tumor could be originated in the lung. The lung tumor was then excised by a thoracoscopy-assisted right S8 resection. Pathological findings were consistent with those of the liver, which confirmed that the lung was the primary site and the liver was the metastatic site. TTF-1 staining was useful to determine the primary site of neuroendocrine tumor developed in the liver.

A 31-year-old man presented to the emergency department with complaints of right lower abdominal pain and vomiting. Laboratory data showed elevated levels of inflammatory markers, and contrast-enhanced computed tomography showed ascitic fluid in the pelvis and an inflamed appendix with a stone. The patient was hospitalized for antibiotic treatment. Seven days after admission, CT showed a pelvic abscess. Antibiotic treatment was continued, but the pelvic abscess did not improve. Endoscopic ultrasonography-guided transrectal drainage was performed on the 21st day after admission. On laboratory examination, the inflammatory reaction improved the next day. The patient was discharged on the 9th day after drainage therapy (30th day after admission). Four months later, laparoscopic interval appendectomy was performed, and the patient was discharged without any complications. This case shows that endoscopic ultrasonography-guided transrectal drainage is effective for preoperative treatment of a pelvic abscess with appendicitis.

A 67-year-old woman was diagnosed with stage IV lung adenocarcinoma and received active chemotherapy. The following year, she underwent an emergency Hartmann's procedure (HP) for sigmoid colon perforation with panperitonitis. Although the ostomy was complicated by a parastomal hernia 12 months later, she did not undergo surgical intervention for this ostomy-related complication due to the advanced staged lung cancer treated actively by pembrolizumab. Pemphigoid and skin ulceration around the stoma, which were thought to be associated with pembrolizumab, were observed, and she was treated conservatively. Three years after the HP, she was brought to our clinic because she developed spontaneous rupture of a parastomal hernia and small bowel evisceration with strangulation, and emergency surgery was performed. A nonviable small bowel segment and the hernia sac were resected, anastomosis was performed, and the abdominal wall was simply closed. The patient's postoperative course was uneventful. This case of a parastomal hernia as a rare stoma-related complication with skin ulceration and prolapse of the small intestine due to rupture of the abdominal wall during pembrolizumab therapy is reported.

A rare case of acute acalculous cholecystitis associated with infectious mononucleosis is presented. A 22-year-old man was referred to our hospital for evaluation of a 3-day history of high-grade fever and sore throat and a 2-day history of abdominal pain. On physical examination, Murphy's sign was present, and computed tomography showed edema and thickening of the gallbladder wall accompanied by hepatosplenomegaly. On laboratory examination, there were increased numbers of atypical lymphocytes. Laparoscopic cholecystectomy was performed for acute cholecystitis on the first day ; evaluation of the resected specimen showed acute acalculous cholecystitis. High-grade fever continued until postoperative day (POD) 12. Hepatobiliary enzyme levels increased postoperatively and peaked on POD 5, and atypical lymphocyte numbers increased until POD 11, with a subsequent decrease in their number. Based on the clinical findings, infectious mononucleosis was diagnosed. Epstein-Barr (EB) virus infection was suspected, but not confirmed serologically. The patient was discharged on POD 16 without any complaints. Most patients with acute acalculous cholecystitis and infectious mononucleosis show spontaneous recovery, and indications for cholecystectomy should be carefully considered during follow-up.

A pancreatic arteriovenous malformation is a rare entity, and there have been very few reports of pancreatic arteriovenous malformations with an aneurysm. A 55-year-old man underwent distal gastrectomy with D1+ lymph node dissection for early gastric cancer 2 years earlier. Two years later, a cystic tumor, 3.6 cm in length, appeared at the tail of the pancreas. The patient had no symptoms and no findings of recurrence. Surgical resection for both definitive diagnosis and treatment was planned. Histopathological findings showed breakdown of the abnormal vessels, which was compatible with a pancreatic arteriovenous malformation associated with an aneurysm. A postoperative pancreatic fistula after gastrectomy induced this curious condition. Careful attention to the pathology is needed after upper abdominal surgery with lymphadenectomy.