Cushing's syndrome produced by a bronchial carcinoid tumor

A case of bronchial carcinoid tumor with ectopic corticotropin production is described. Cushing's syndrome refractory to therapy, including pituitary irradiation and hypophysectomy, had been present for 12 years before the neoplasm was discovered at autopsy. The tumor was a small nodule localized in the pulmonary parenchyma and an adjacent hilar lymph node. Corticotropin, serotonin, and neuron-specific enolase were localized in the neoplasm by immunoperoxidase staining.