An ectopic ACTH-producing carcinoid tumor localized by the measurement of ACTH in the bronchial lavage

We report a case of an ectopic ACTH-producing carcinoid in the lung. Typical Cushingoid appearance, elevated plasma ACTH and serum cortisol, bilateral enlargement of the adrenal glands, absence of pituitary adenoma and negativity in petrosus sinus venous sampling indicated the ectopic ACTH syndrome. Venous samplings from a lung tumor which was detected by the chest X-ray, did not show any step-up of ACTH. However, ACTH concentration in the bronchoscopic lavage was as high as that in the peripheral blood. Removal of the tumor, which was an ACTH producing carcinoid, resulted in normalization of ACTH and cortisol concentrations. Measurement of ACTH in the bronchoscopic lavage was useful for the diagnosis of ectopic ACTH-producing tumor.