Two cases of hypouricemia in association with malignant diseases are presented. One patient had metastatic breast cancer and the other an undifferentiated
retroperitoneal sarcoma of the childhood. Uric acid renal handling was studied with the pyrazinamide and benzbromarone tests. Both patients had
reduced postsecretory reabsorption of uric acid. The increase of serum uric
acid levels in both patients, after a partial response to chemotherapy, indicates
the possible paraneoplastic origin of hypouricemia. Our results are discussed
and compared with other reports in the literature.
