Extensive endothelial replacement by tumor cells in the portal system: an autopsy case of intrahepatic cholangiocarcinoma.

An autopsy case of intrahepatic cholangiocarcinoma (ICC) with a peculiar form of extensive portal invasion is reported here. A 76-year-old woman presented with anorexia and abdominal discomfort. A high level of serum carbohydrate antigen 19-9 and endoscopically detected esophageal varices were found. Obvious mass lesion was not identified on CT scan and no portal blood flow was found. The patient died 6 months after admission. At autopsy multiple irregular shaped tumors in the liver were found. The size of the largest one was 3 x 2 cm. These tumors were well-differentiated adenocarcinomas with partial mucinous carcinoma morphology. Surprisingly, portal veins contained mucinous fluid and the inner surface was lined with a single layer of tumor cells but not endothelial cells. Invasion of carcinoma into the tissue outside the blood vessels was hardly observed in organs other than the liver. This form of extensive invasion of the tumor, termed intimal carcinoma spreading, caused complete obstruction of the portal system. To our knowledge there has been no report on this type of portal invasion of ICC.

Pancreatic endocrine tumor with partial acinar cell differentiation.

We examined a 70-year-old woman in whom a pancreatic endocrine tumor with partial acinar cell differentiation had been diagnosed. She had neither endocrine nor exocrine symptoms. The tumor was located in the pancreatic tail and measured 12.5 x 9.5 x 8 cm. It had a capsule, was composed of multiple adhesion nodules, and was elastically soft, medullary, and yellowish white. The neoplastic cells had large, irregular, oval nuclei; prominent eosinophilic nucleoli; and abundant eosinophilic cytoplasm with many fine granules. The cells had proliferated in islet-like solid medullary, trabecular, acinar, and papillary patterns. Most neoplastic cells were strongly positive for synaptophysin. 10 to 25% of the neoplastic cells were positive for alpha1-antitrypsin. Neuroendocrine and zymogen granules were simultaneously observed in the cytoplasm of the same neoplastic cells at the ultrastructural level. The tumor may be considered an amphicrine tumor.