Hyperplastic and neoplastic endocrine cells of the pancreas in aspiration biopsy

Aspiration biopsy of four primary endocrine tumors of the pancreas showed single and large sheets of tumor cells. Tumor cells were polygonal in shape with ill-defined, filmy or granular cytoplasm and regular round nuclei containing a finely granular chromatin pattern and inconspicuous or prominent nucleoli. Focal gland-like arrangement was seen in several sheets of tumor cells. Aspirate from liver metastases of an endocrine tumor of the pancreas showed single and clustered oval cells with granular cytoplasm and eccentrically located round and hyperchromatic nuclei. Smears prepared from aspirates of three fibrotic pancreata containing nodules of hyperplastic endocrine cells showed smaller fragments of endocrine-cell epithelium with focal gland-like arrangement. Individual hyperplastic endocrine cells displayed granular, filmy, and ill-defined cytoplasm and round to oval hyperchromatic nuclei showing a finely granular chromatin pattern. Nuclear pleomorphism was noted in some cell groups.