Purpose: Gastric dilatation due to food retention after gastrectomy is a risk factor for aspiration pneumonia and a prolonged hospital stay, but there is no clear index to define gastric dilatation. In this study, we aimed to identify a clinical index associated with therapeutic intervention for gastric dilatation after gastrectomy, based on abdominal X-ray radiography. Materials and Methods: Of 95 patients who underwent distal gastrectomy at Kitasato University Hospital between January and August 2019, 77 were examined by abdominal X-ray radiography after gastrectomy. The maximum width of the gastric bubble, the distance from the inferior border of the diaphragm to the superior border of the gastric bubble (thickness of the gastric wall), and the vertical diameter of the stomach were measured, and then corrected by the distance from the center of the vertebral body to the left diaphragm angle. Relationships between the measured values and the need for therapeutic intervention were analyzed using ROC curves. Results: Among the 77 cases, 5 required therapeutic intervention. The index most strongly associated with therapeutic intervention was the distance from the center of the vertebral body to the left diaphragm angle relative to the maximum width of the gastric bubble (defined as the gastric dilatation index). The optimal cutoff for this index for predicting therapeutic intervention was 51.0%, with a sensitivity of 100%, specificity of 86%, and AUC of 0.94. Conclusion: The gastric dilatation index in an abdominal X-ray examination may be useful for prediction of the need for therapeutic intervention for gastric dilatation after gastrectomy.

A 73-year-old man underwent distal gastrectomy followed by Roux-en-Y reconstruction with D2 lymph node resection for gastric cancer, and thereafter received adjuvant S-1 chemotherapy for one year. Three years after gastrectomy, metastasis of the gastric cancer to the transverse colon was found, and transverse colectomy was performed. The pathological diagnosis was colon metastasis of gastric cancer, and S-1 chemotherapy was given for one more year after colectomy. Five years and four months after gastrectomy, swelling and pain developed in the right femoris muscle. CT and MRI showed a tumor of 80×70 mm in size in the right biceps femoris muscle. An incisional biopsy of the right femoris muscle was performed, and pathological findings showed poorly differentiated adenocarcinoma compatible with muscle metastasis of the gastric cancer. Since there was no obvious primary tumor in any other organs, we diagnosed the patient with femoris muscle metastasis from gastric cancer. Colon metastasis from gastric cancer is rare and there are only a few reports of asynchronous metastasis to the skeletal muscle.

Bile duct metastasis is extremely rare as a cause of biliary stenosis in patients with distant metastases from gastric cancer. The patient was a 71-year-old male who underwent distal gastrectomy for synchronous gastric cancers in January 2014, and remnant gastrectomy for gastroesophageal cancer in March 2020. In October 2020, the patient was referred to our hospital due to a hilar bile duct tumor and intrahepatic bile duct dilation. Enhanced CT showed circumferential stenosis of the hilar bile duct, which was classified as Bismuth IV. A biopsy of the hilar bile duct tumor did not show malignant findings, but the patient was diagnosed with unresectable perihilar cholangiocarcinoma based on the imaging findings, and chemotherapy was administered for 6 months. Due to a marked decrease of tumor markers and tumor shrinkage, conversion surgery was planned, and left hepatectomy and caudate lobectomy with combined resection of the portal vein were performed. Pathologically, the tumor was diagnosed as a poorly differentiated adenocarcinoma and signet-ring cell carcinoma that grew mainly around the bile duct, similar to the gastroesophageal cancer specimen. There was no dysplasia of the bile duct mucosal epithelium, so the patient was diagnosed with bile duct metastasis from gastroesophageal cancer. Three months after surgery, the patient died of sepsis from cholangitis due to biliary anastomosis stenosis caused by local recurrence.

The patient was a 23-year-old man who was diagnosed with locally advanced cancer of the pancreatic head and associated invasion of the inferior vena cava. He was treated with four cycles of 1,000 mg/m² gemcitabine+125 mg/m² nab-paclitaxel chemotherapy, with three administrations and one rest period in each cycle. After chemotherapy, diagnostic imaging showed that the primary lesion had contracted by 41%, and pancreatic head and duodenal resection was performed, along with inferior vena cava resection. Histopathological images of resected samples showed fibrosis and inflammatory cell invasion, which were considered to be effects of chemotherapy. No viable cancer cells were visible and a complete pathological response was assumed to have been achieved. The patient was administered 120 mg/body/day S-1 orally as postoperative adjuvant chemotherapy. At 21 months after surgery, and 30 months after definitive diagnosis, the patient is currently alive without recurrence.

A 72-year-old man was found to have splenomegaly and an intrasplenic mass in a medical examination. Hamartoma, inflammatory pseudotumor, and sclerosing angiomatoid nodular transformation (SANT) were included as differential diagnoses, but malignant disease could not be ruled out; therefore, laparoscopic splenectomy was performed. A postoperative peripheral blood test showed extreme thrombocytosis and pseudo-hyperkalemia. Thereafter, the patient was diagnosed with essential thrombocythemia and myelofibrosis, with a mutant JAK2-V617F gene. The pathological diagnosis was focal nodular extramedullary hematopoiesis (EMH). EMH sequentially occurs in many hematological disorders, and sometimes presents as hematopoietic masses at several sites; however, presentation as a nodular mass localized in the spleen is rare. It is extremely difficult to diagnose EMH in patients without a past medical history of hematological disorders. However, for a focal nodular mass of the spleen, it is important to determine the treatment strategy with consideration of potential hematological diseases and extramedullary hematopoiesis.

The patient was a 54-year-old male diagnosed with lower rectal cancer (Rb-Ra, type 2, cT3(A), cN1a, cM0: cStage IIIb) who underwent surgery after neoadjuvant chemotherapy. He received a standard mechanical bowel preparation preoperatively, but excretion of stool was incomplete and muddy stool persisted until just before the operation. Partial internal sphincter resection via transanal total mesorectal excision (TaTME) combined with robotic surgery and D2 lymph node dissection with diverting ileostomy was performed. Diarrhea occurred immediately after surgery and there was a marked increase in the inflammatory response on postoperative day (POD) 3. Rectal examination confirmed anastomotic failure and a transanal drain was placed in the pelvic cavity. Contrast-enhanced CT revealed a retroperitoneal abscess, and subsequently percutaneous abscess drainage was carried out. The abscess gradually reduced in size and the patient was discharged on POD 50. We report this case as an important illustration that retroperitoneal emphysema probably caused by high pressure of the pneumopelvis during TaTME can easily lead to spread of anastomotic leak to the retroperitoneum.