A comparative study of 14 cases of familial and nonfamilial pheochromocytomas.

A comparison is made between epidemiological features found in a group of 14 patients with familial and nonfamilial pheochromocytomas at M. D. Anderson Hospital and Tumor Institute. The Sipple syndrome (familial) group comprised eitht patients from three different families, and the nonfamilial group consisted of six nonrelated patients. The main differences were noted in the age of onset, sex ratio, bilaterality, malignant behavior, and occurrence of a second nonendocrine primary tumor. An attempt was made by light microscopy to define features that would indicate malignant behavior. No such features could be delineated. Survival time was unrelated to the presence of pheochromocytoma except in operative and investigative procedures.