It is now recognized that there is considerable variation in the clinical manifestations,1,2 the origin, and character of metastatic carcinoid tumors. A malabsorption syndrome3 and scleroderma4 may accompany the carcinoid syndrome. This syndrome may be produced by bronchial carcinoids with metastases,5-8 oat-cell carcinoma,9 argentaffinoma of the lung without hepatic metastases,10 and pancreatic carcinoma with demonstrated 5-hydroxytryptophan decarboxylase activity.11 The syndrome is apparent in only 20% of patients with carcinoid tumors and hepatic metastases12 and may rarely be associated with normal levels of 5-hydroxyindoleacetic acid (5-HIAA) excretion in the urine.13,14
The possible association of carcinoid syndrome and Cushing's syndrome has been suggested by the report of Harrison15 of a patient with bronchial carcinoma and clinical features of adrenal hyperplasia. In their patient 17-ketosteroid excretion was normal and 5-HIAA excretion in the urine was moderately increased as shown by paper chromatography.