Concurrent Cushing's and Zollinger-Ellison syndromes in a patient with islet cell carcinoma. Case report and review of the literature.

This report documents the simultaneous occurrence of Cushing's and Zollinger-Ellison syndromes in a patient with islet cell carcinoma. The clinical concurrence of these two syndromes has been recorded in only three previous case studies, while three other case reports record evidence suggesting the presence of both gastrin and ACTH within the tumor but without clinical sequelae. In the present report, evidence based on multiple clinical and biochemical data supports the concept that both syndromes are a result of "ectopic" hormone production by the tumor.