Activities in Detection of Ectopic ACTH Producing Tumors

Abstract

A study group on ectopic hormone-producing tumor was organized in Japan in 1967. During the first three years, this group conducted endocrine screening tests on 438 cases of malignant tumor consisting mainly of carcinoma of the lung, and detected ectopic ACTH-producing tumor in four cases of carcinoma of the lung and one case of carcinoma of the colon. It was noted that typical clinical signs of Cushing's syndrome were lacking in all five cases, suggesting the importance of screening tests. In all these cases, urinary excretion of 17-OHCS and the level of plasma cortisol, which dexamethasone failed to suppress, were high. Clinical picture revealed edema, pigmentation and hypertension. Laboratory findings included hypokalemia and a high degree of impairment of glucose tolerance. Concentration of ACTH in tumor tissue measured by radioimmunoassay was considerably higher than that measured by bioassay.