Hormone-producing capabilities of renal cell carcinomas. Correlation with ultrastructural findings

A retrospective study was conducted to evaluate ultrastructural aspects of hormone production by renal cell carcinomas. Fifteen renal cell carcinomas examined ultrastructurally were retrieved from the files. Six cases revealing abundant and diffusely distributed secretory granules in the neoplastic cells were found and correlated with clinical manifestations and laboratory findings. Five of these patients were hypercalcemic; the sixth patient was asymptomatic, and no abnormalities were detected in routine laboratory workup. Two additional cases showed focal aggregates of electron dense neurosecretory granules. These last 2 patients had no biochemical abnormalities and were entirely asymptomatic. The size and ultrastructural morphology of the cytoplasmic granules identified in the renal neoplasms were compared with the usual granular morphology associated with the specific hormones involved. Immunohistochemistry was used to confirm the parathormone hormone content of the granules in 7 of the 8 cases presented. The other case revealed granules with ultrastructural characteristics of prostaglandin granules.