Pheochromocytoma : Cytologic findings on intraoperative scrape smears in five cases

There have been few studies describing the cytology of adrenal pheochromocytoma (PC). Although fine needle aspiration (FNA) for a preoperative diagnosis of PC is generally considered a contraindication, this tumor can be an unsuspected finding in adrenal FNA performed for other reasons. Scrape cytology smears prepared in five cases of PC were examined for different cytomorphologic features. The results were correlated with the corresponding permanent histologic sections. Previously described features, like cellular smears showing cells with abundant, poorly defined fragile cytoplasm, bare nuclei, anisonucleosis, "salt and pepper" chromatin, variable nucleoli and few ganglion cell-like cells, were noted. In addition, several previously unreported cytologic features were observed: (1) loosely cohesive PC cells along a ramifying, delicate central core; (2) intracytoplasmic microvesicular (not hyaline/homogeneous) globules; and (3) different arrangements of capillary-stroma and PC cells (Zellballen pattern; empty capillary rings; stroma with adherent, intact PC cells or fragments of disrupted PC cell cytoplasm). The cytologic appearance of PC may resemble that of other neuroendocrine tumors; however, it can be diagnostic when combined with proper clinical data and ancillary tests.