Cutaneous Manifestations of the Malignant Carcinoid Syndrome

Abstract

A patient with the malignant carcinoid syndrome is described in whom the unusual cutaneous manifestations of severe total body pruritus and intermittent orange blotches were the predominant features. The patient''s course is noted in some detail and the results of several therapeutic trials were noted. He demonstrated a variable response to serotonin antagonists. Dietary tryptophan restriction resulted in clinical and biochemical improvement on a short term trial but longer attempts at this were not carried out because of the low baseline niacin metabolite excretion. The results of skin biopsy assays for serotonin and histamine were reported which indicated loss of local serotonin and histamine during the orange flush. Cardiac catheterization demonstrated the presence of pulmonary stenosis and tricuspid insufficiency and blood samples for serotonin taken at varying sites showed no significant differences. The importance of the early recognition of the cutaneous manifestations of the malignant carcinoid syndrome was emphasized.