A 72-year-old woman had undergone left mastectomy for invasive lobular carcinoma 6 years ago. She developed jaundice during follow-up, and abdominal enhanced CT revealed a 19-mm mass in the duodenal papilla. Histopathological examination of endoscopic ultrasound-guided fine-needle aspiration biopsy revealed atypical cells, which led to diagnosis of primary duodenal papillary cancer. Subtotal stomach-preserving pancreaticoduodenectomy was performed. Histopathological examination revealed a well-defined nodular lesion in the duodenal papilla that exhibited the pathological features of primary breast cancer. An immunohistopathological examination confirmed metastasis of breast cancer to the duodenal papilla. During postoperative follow-up, uterine metastasis was detected and systemic chemotherapy was administered. However, peritoneal disseminated metastases and brain metastasis were subsequently detected, and the patient died 11 months after the pancreatic surgery. Gastrointestinal metastasis of breast cancer has been reported in several cases, but duodenal papilla metastasis is extremely rare. Here, we report a case of resection of duodenal papilla metastasis that developed with obstructive jaundice 6 years after surgery for breast cancer.

A 61-year-old man who had undergone surgery for renal cell carcinoma 11 years ago was found to be positive for fecal occult blood. CT was performed and tumors were found in the body and tail of the pancreas and liver flexure of the colon. Total colonoscopy showed that the colorectal tumor was a submucosal tumor-like protuberant hypervascular lesion, but a biopsy did not provide a definitive diagnosis. Based on the clinical course, recurrence of renal cell carcinoma with pancreas and colon metastasis was diagnosed. Distal pancreatectomy and partial resection of the transverse colectomy were performed. After surgery, a pancreatic fistula was found, followed by focal peritonitis, omental necrosis, and an intraabdominal abscess. The patient improved with conservative treatment including CT-guided drainage and was discharged from hospital on the 88th postoperative day. Colon metastasis from renal cell carcinoma is extremely rare and metastasis to multiple organs is often observed. In addition to surgical resection, drug therapy with immune checkpoint inhibitors is effective in some cases, but further investigation is needed. In surgical excision of a colorectal tumor in the transverse colon, the pancreatic transection and colonic anastomosis are close to each other, and this may contribute to the relationship between pancreatic fistula and infection.

A 57-year-old man presented with abnormal bowel movement and was diagnosed with rectal cancer that had metastasized to the liver and lungs. The patient underwent laparoscopic low anterior resection at our hospital. A diverting loop ileostomy was created because an intraoperative air leak test was positive. From postoperative day 10, the patient suffered from high ileostomy output (stoma output ≥2,000 ml/day). Antidiarrheal drugs were administered, but were not effective. On postoperative day 20, the patient revealed that he had been consuming 12 xylitol-containing candies (15.5 g xylitol) per day. The stoma output significantly decreased to 300–500 ml/day right after the patient stopped eating these candies. Xylitol is a common artificial sweetener used in sugar-free confectionery and excessive intake of xylitol is known to cause diarrhea due to its poor absorption. This case suggests that intake of an excessive amount of xylitol can be a cause of high output syndrome for patients with ileostomy.

A 37-year-old man visited another hospital with complaints of abdominal distention, anorexia, and weight loss. He was referred to our hospital. CT showed massive ascites, a descending colon tumor, and peritoneal dissemination. A colonoscopy revealed a fully circumferential irregular type 1 tumor in the descending colon. FDG-PET showed FDG accumulation in the descending colon tumor, supraclavicular fossa, mediastinum, paratrachea, peritoneum, and omentum. Biopsy of the descending colon tumor failed to provide a definite diagnosis. Therefore, staging laparoscopy was performed. Immunohistochemical staining was positive for nuclear protein of the testis (NUT) and fluorescence in situ hybridization (FISH) showed rearrangement of the NUT gene. Therefore, the patient was diagnosed with NUT midline carcinoma and treated with multiagent chemotherapy. However, due to rapid progression of the disease, he passed away about six months after the initial diagnosis. NUT midline carcinoma is a very rare disease with a genetic abnormality, and is often detected at an advanced stage without any disease-specific histology. Effective treatment for NUT midline carcinoma has not been established, and further studies and accumulation of cases are needed.

A 75-year-old man underwent a right hemicolectomy for ascending colon cancer at age 72. Adjuvant chemotherapy was performed due to postoperative diagnosis of a high-risk stage IIb tumor. During the follow-up period, a bulge in the left inguinal region was observed and CT revealed a left spermatic cord tumor. Left orchiectomy was performed three years after the primary operation. Histological examination of the resected specimen revealed tubular adenocarcinoma, which was probably a metastasis from the ascending colon cancer. Based on the intraoperative findings of a high risk of recurrence, local radiation therapy and chemotherapy were performed. Spermatic cord metastasis from colon cancer is extremely rare and is associated with a poor prognosis. Metachronous metastasis can occur after a relatively long time and may be asymptomatic, often leading to delayed diagnosis. Spermatic cord metastasis should be considered in a patient with a malignant tumor who presents with an inguinal bulge.

Neuroendocrine neoplasm (NEN) located in the pelvis is very rare. In this study, we report a case of NEN in the anterior sacral region that was treated by surgical resection. The patient was a 69-year-old woman who had been diagnosed with a pelvic tumor in the anterior sacral region with a cystic component 7 years ago. Laparoscopic resection of the pelvic tumor was performed as diagnostic treatment because CT and MRI suggested a primary neurogenic tumor and malignancy could not be ruled out due to the slow growth trend. The histopathological diagnosis was NET G1 and the tumor was considered to be primary in the anterior sacral region. The patient is alive 1 year and 4 months after surgery without recurrence. NEN is known to be associated with lymph node metastasis and distant metastasis, and the recurrence rate after resection is relatively high. Therefore, NEN should be included in the differential diagnosis of tumors arising in the anterior sacral surface, and surgical resection should be considered.