A CASE OF RENIN PRODUCING LEIOMYOSARCOMA ORIGINATING IN THE LUNG

A 54-year-old woman was referred to our hospital for the treatment of a tumor of the right chest wall. Clinical examination revealed hyperte nsion, hypokalemia, metabolic alkalosis, hyperaldosteronism and hyperr eninemia. Computed tomography and an abdominal echogram indicated a tu mor in the right phrenic area and two tumors in the retroperitoneum ne ar the pancreas head. After the surgical resection of these tumors, th e primary reninism was diminished. The pathological diagnosis of these tumors was leiomyosarcoma. Plasma active and inactive (trypsin-activa ted) renin activities (PRA) were 85.7 and 38.9 ng angiotensin I/ml/h, respectively. These PRA did not respond to either postural stimulation or suppression by the volume expansion. Active and inactive renin act ivities in a right phrenic area tumor were 208 and 32 ng angiotensin I /mg protein /h, respectively. Those of an abdominal tumor were 196 and 30 ng angiotensin I/mg protein/h, respectively. Renin mRNA identical in molecular size to that of the human kidney was identified by northe rn blot analysis. This is the first case report of renin producing lei omyosarcoma derived from the lung, which is characterized by relativel y lower plasma prorenin concentrations.