SYNDROME OF INAPPROPRIATE SECRETION OF ANTIDIURETIC-HORMONE FOLLOWINGINTRATHORACIC CISPLATIN

A case of malignant thymoma with pure red cell aplasia (PRCA) complica ted by syndrome of inappropriate secretion of antidiuretic hormone (SI ADH) following intrathoracic cis-dichlorodiammine platinum (CDDP) admi nistration is reported. A 59-year-old Japanese woman who presented wit h severe general fatigue was diagnosed with PRCA associated with a thy moma, based on the findings of a bone marrow biopsy, computed tomograp hy of the chest, and the existence of anti-acetylcholine receptor anti bodies. She underwent a thymectomy after frequent blood transfusions. This was followed by intrathoracic CDDP administration, because of ple ural dissemination. Nine days following chemotherapy, her serum sodium concentration was found to be 104 mM, while her consciousness was dro wsy with severe fatigue and vomiting. This hyponatremic state was diag nosed as SIADH induced by CDDP infusion into the thoracic space, based on the hypo-osmolality of her serum, the hyper-osmolality of her urin e, and an inappropriate level of plasma vasopressin.