Ectopic GHRH-secreting
tumors, such as
carcinoid, rarely cause
acromegaly. As protracted exposure to high levels of GH is associated with considerable morbidity and mortality, these patients require early and effective medical
therapy to control hormonal hypersecretion. We employed a prolonged release
somatostatin analog,
lanreotide, to treat a patient with disseminated GHRH-producing
carcinoid. Before treatment, the patient had a biochemical profile characteristic of active
acromegaly. Plasma GHRH levels were markedly elevated (200-fold), and urinary 5-hydroxyindolacetic
acid (5-HIAA) levels were increased (4-fold). Magnetic resonance imaging revealed a large asymmetrical pituitary mass consistent with somatotroph
hyperplasia.
Somatostatin receptor scintigraphy revealed multiple bony and soft tissue lesions as well as striking pituitary uptake.
Lanreotide (30 mg) was administered weekly by im injection for 12 weeks. Rapid and sustained symptomatic clinical improvement with diminished soft tissue swelling and
hyperhidrosis was observed. GHRH levels decreased by 70%;
glucose-suppressed GH and
insulin-like growth factor I levels were reduced by 90% and 75%, respectively, to near normal values; urinary
5-HIAA levels normalized; and the pituitary mass remained unchanged. Unfortunately, the patient died due to complications of
osteogenic sarcoma. In conclusion, prolonged release
lanreotide induced clinical and biochemical remission in this patient with diffusely metastatic GHRH-producing
carcinoid. This long-acting
drug thus offers an effective, well tolerated, and convenient medical
therapy for control of hormonal hypersecretion induced by excess GHRH.