Yoshihito Masuoka

A case study of a collision tumor composed of cancers of the bile duct and pancreas

In this case report, we describe the extremely rare case of a collision tumor comprising cancers of the bile duct and the pancreas. A 70-year-old man was referred to our hospital with a diagnosis of obstructive jaundice. He was diagnosed with pancreatic head cancer, and we performed a pancreaticoduodenectomy with lymph node dissection. At laparotomy, there were two palpable masses in the vicinity of the confluence of the cystic duct and the head of the pancreas. The resected specimen demonstrated tumors at the confluence of the cystic duct and in the pancreatic head. Histopathological examination demonstrated a moderately differentiated tubular adenocarcinoma in the pancreatic head and a well-differentiated tubular adenocarcinoma at the confluence of the cystic duct. Immunostaining was negative for p53 and MUC6 in the pancreatic head tumor; however, immunostaining was positive for both in the tumor located at the confluence of the cystic duct. The two tumors were histologically different and were diagnosed as collision cancer caused by the collision of the bile duct and pancreatic cancers.

Carcinosarcoma of the ampulla of Vater: a case report and literature review

BackgroundCarcinosarcoma of the ampulla of Vater is extremely rare, and to the best of our knowledge, this is the third reported study.Case presentationThe patient was a 73-year-old man, who presented with a chief complaint of dark urine. After a work-up, we suspected duodenal papillary cancer and performed a subtotal stomach-preserving pancreaticoduodenectomy with lymph node dissection. Immunohistochemically, the sarcomatous atypical cells were diffusely positive for cytokeratin AE1&3 and vimentin and focally positive for α-smooth muscle actin; these cells were also negative for desmin, CD34, DOG1, c-kit, and S100. From these findings, we diagnosed the patient with so-called carcinosarcoma. There was no lymph node metastasis.ConclusionsCarcinosarcoma of the ampulla of Vater has a poor prognosis, and lymph node metastases are often seen. For the complete cure of carcinosarcoma of the ampulla of Vater, resection with the dissection of the lymph nodes may be necessary.

Laparoscopic splenopancreatectomy for an endocrine tumor with cystic changes: a case report

The biological behavior of a cystic pancreatic endocrine neoplasm is less aggressive than that of pancreatic neuroendocrine neoplasms, and its prognosis is better. Limited surgery should be considered for cystic pancreatic endocrine neoplasms that are not accompanied preoperatively by lymph node or distant metastasis.