The association of malignancy with nephrotic syndrome and renal histopathologic abnormalities is well documented. We report a case of intravascular lymphomatosis (IVL) presenting as nephrotic syndrome which was diagnosed by renal biopsy. Histological examination of the renal biopsy specimens showed dissemination of neoplastic lymphoid cells throughout the glomerular capillary bed. These tumor cells were positive for CD20. Since the nephrotic syndrome improved with treatment of the lymphoma, intravascular lymphomatosis may well have played an important role in the pathogenesis of minimal change nephrotic syndrome in this patient.
(Internal Medicine 42: 98-101, 2003)