Occult secretion of acth and bilateral adrenalectomy: sometimes the messenger has to be shot

Cushing's syndrome due to ectopic adrenocorticotrophic hormone (ACTH) secretion is infrequent, the most frequent cause being bronchial carcinoid; nevertheless, in a considerable proportion of cases (up to 16%), the origin of ACTH secretion is not found. Treatment of Cushing's syndrome due to ectopic ACTH secretion is surgical resection of the tumor. However, surgical excision is not always feasible, either because the tumor has not been located, or because it is unresectable; in these cases the question is when to carry out a bilateral adrenalectomy. We present a case of ACTH-dependent hypercortisolism, in which the ectopic origin of ACTH secretion was established from the results of complementary tests (suppression tests, petrosal sinus sampling, imaging); nevertheless, none of the imaging tests was able to identify the secreting tumor. Consequently, after a reasonable interval, a bilateral adrenalectomy was performed, with good clinical results.