[Renal disease in myeloma. Role of the tumor cell mass (author's transl)].

Out of a group of 57 patients with the diagnosis of multiple myeloma fourteen (25%) with different degrees of renal disease were selected. Bence-Jones (BJ) proteinuria, infections, and, above all, the tumoral cell mass were the three main factors implicated in the development of myeloma associated renal disease. Only 13% of IgG myelomas presented with renal failure as compared to 27% of IgA myelomas. The patients with BJ and IgD myeloma, classically those with a higher tendency to develop renal disease (in our series 37% of BJ myelomas and 50% of IgD myelomas had renal disease), had the biggest tumoral cell mass of all patients studied. The relationship between tumor cell mass and renal disease in myeloma is supported by the recovery of renal function in a patient with chronic renal failure after a treatment-induced reduction of the tumoral cell mass from 1.71 to 0.82 x 10(12) cells/m2 body surface.