A 69-year-old woman with Cushing's syndrome due to A C T H production by a pancreatic tumor had hypokalemia, osteoporosis, muscle wasting, a n d avascular necrosis of the humeral heads. She h a d a n excellent response to bilateral adrenalectomy. These a n d other clinical a n d pathophysiologic aspects of the ectopic A C T H syndrome are discussed. The pancreatic tumor was histologically compatible with either an islet cell or a carcinoid tumor. T h e evidence for the histologic and functional overlap of these two types of tumor is reviewed.
DRENOCORTICAL HYPERFUNCTION ASSOCI-
A ated with neoplasms arising outside the pituitary and the adrenal glands is well known. In 1928, Browns reported a woman with hyperpigmentation, florid appearance, hirsutism, diabetes mellitus, and polycythemia, who was found at necropsy to have an oat cell carcinoma of the lung and adrenal hyperplasia. Since that time, numerous instances of Cushing's syndrome secondary to "non-endocrine" neoplasms have been reported. Approximately one half of these have been secondary to tumors of the lung, while those of the thymus and pancreas have each accounted for about 10%.5340 Of the pancreatic neoplasms, only 17 have been islet cell tumors (Table l), and one has been a carcinoid.25 Carcinoid tumors, whatever their origin, are only infrequently associated with Cushing's syndrome (Table 2). We present here a patient with a pancreatic tumor histo-