A 64-year-old man was admitted for epigastralgia. Abdominal CT showed an enhanced tumor at the lower biliary duct causing obstructive jaundice. Tumor cells with high nuclear-cytoplasmic (N/C) ratio and rosette formation were confirmed by biopsy. Immunostaining findings were positive for chromogranin A，synaptophysin, and neuron specific enolase. Preoperatively, we suspected neuroendocrine carcinoma (NEC) of the bile duct, and performed subtotal stomach-preserving pancreatoduodenectomy. Histological examination of the specimen demonstrated large cell NEC of the bile duct. The Ki-67 index was 40%. As adjuvant chemotherapy, tegafur-gimeracil-oteracil potassium was administered for 24 months, and he has no evidence of recurrence after surgery. NEC of the bile duct are rare and highly malignant diseases with a dismal prognosis. To the best of our knowledge, 50 cases of biliary NEC have been reported in Japan, and only 6 cases of biliary large cell NEC have been reported in the English literature. Analysis of reported cases indicates that curative resection can improve survival rate among patients with biliary NEC. Further evaluation is needed to elucidate optimal adjuvant therapy for biliary NEC.

A 33-year-old man was admitted with acute lower abdominal pain. A bulky tumor, ascites, and free air were indicated by abdominal computed tomography. We diagnosed the patient with perforative peritonitis and performed emergency surgery. Laparotomy showed that the tumor originated from the ileocecal mesentery and infiltrated the ileum. Ileocecal resection was performed. Pathological findings showed that spindle-shaped tumor cells grew proliferously with a patternless pattern. Immunohistochemistry findings showed that tumor cells were positive for CD34 and negative for c-kit, desmin, and S-100. Therefore, we diagnosed the patient with solitary fibrous tumor (SFT). Perforative peritonitis was thought to be caused by the penetrated ileum. SFTs are uncommon mesenchymal neoplasms of ubiquitous location, observed in middle-aged adults. This is the first report about a SFT presenting with perforative peritonitis.