Neuroendocrine carcinoma of the pancreas diagnosed by aspiration cytology. A case report.

Cytologic criteria for distinguishing endocrine from exocrine carcinomas of the pancreas have not been previously elucidated. A case is presented in which the diagnosis of neuroendocrine carcinoma was made on fine needle aspirates of a pancreatic mass and hepatic metastases in a 33-year-old female. Cytologically, the aspirated tumor resembled an intermediate-cell neuroendocrine carcinoma of the lung rather than the usual duct-cell adenocarcinoma of the pancreas. Histologic sections of the subsequently resected primary pancreatic mass revealed a neuroendocrine carcinoma of an intermediate-cell type. Ultrastructurally, the characteristic interlacing cytoplasmic processes with scanty granules were seen. Immunoreactive neuron-specific enolase (NSE), leuenkephalin, substance P and somatostatin were present in the tumor cells in Bouin's-fixed cell blocks of the aspirate; neuron-specific enolase, somatostatin and gastrin were detected in the paraffin-embedded sections of the resected tumor. This variant of pancreatic carcinoma merits recognition as a cytologically distinct group, which shares many of the features described in its bronchopulmonary and gastrointestinal counterparts.