[Ectopic ACTH- or CRH-secreting tumors in Cushing's syndrome]

A collection of 13 tumors causing an ectopic Cushing's syndrome was composed of four bronchial carcinoids, one small cell carcinoma of the bronchus, one thymic carcinoid, two islet cell tumors of the pancreas, one pheochromocytoma, two medullary carcinomas of the thyroid, one prostatic cancer and one intrasellar choristoma. By immunohistochemistry, ACTH in combination with CRH was found in one bronchial carcinoid and in one islet cell carcinoma. ACTH but not CRH was demonstrable in one bronchial carcinoid, in both medullary carcinomas of the thyroid, in the thymic carcinoid and in the pheochromocytoma. CRH without ACTH was present in the small cell carcinoma of the bronchus, one bronchial carcinoid, the prostatic cancer and the choristoma of the sellar region. Neither ACTH nor CRH could be found in one islet cell carcinoma. In the pituitary (n = 7) Crooke's cells were found except in one case with islet cell carcinoma which was treated with adrenostatic drugs. The pituitary besides the intrasellar choristoma harbored an ACTH cell adenoma. The pathophysiological correlations are discussed.