Abstract

Light and electron microscopic observation of a case of functioning pheochromocytoma arising from the right adrenal gland of 67 year old man were made. Chief clinical complaints were paroxysmal hypertension, sweating, palpitation and flushing of the face for 1 year period. Pertinent laboratory findings were 24 hour urinary catecholamine content of 6,307 ㎍ and 25.8 mg of VMA. Hemogram showed 18mg% of hemoglobin and 53% of hematocrit values. Extirpated right adrenal consisted of a well encapsulated tumor mass weighing 30㎎s and measuring 7 cm in the greatest diameter. Cut surface revealed gray to brown color with areas of hemorrhage and necrosis. Microscopically, the tumor showed various shape of large cells containing chromaffin granules in cytoplasm by special staining. On electron microscopy, cytoplasm of the tumor cells was packed with round to oval dense cored secretory granules surrounded by clear halo which are limited by a single membrane. The majority of granules were norepinephrine type and only a few were epinephrine type. Postoperatively, all clinical symptoms disappeared and erythrocytosis returned to normal value.