SYNDROME OF INAPPROPRIATE SECRETION OF ANTIDIURETIC-HORMONE IN A PATIENT AFFECTED BY METASTATIC MELANOMA

The syndrome of inappropriate secretion of antidiuretic hormone (SIADH ) is characterized by hyponatraemia due to water retention resulting f rom the persistent release of antidiuretic hormone (vasopressin). It m ay occur in a variety of malignant and non-malignant conditions, in pa rticular in association with oat cell carcinoma, pulmonary and cerebra l diseases. We report the case of a male patient affected by melanoma of the right temporal region with brain metastasis who developed acute headache, drowsiness, nausea, vomiting and pathological reflexes. Cli nical and laboratory investigations led us to the diagnosis of SIADH. Restriction of fluid intake obtained a good clinical improvement with normalization of laboratory alterations; after 2 months the patient ex perienced a new episode of SIADH which was promptly treated. As melano ma has been occasionally observed in association with SIADH it should be included in the list of tumours that can cause this particular synd rome. (C) 1998 Lippincott Williams & Wilkins.