[Primary renal plasmacytoma. A case report].

We describe a patient with a primary renal plasmacytoma. In the literature available, only six clinical cases have been reported. A 64-year-old patient is presented who had the clinical signs of a renal cell carcinoma. Histological examination after nephrectomy, however, revealed a plasmacytoma. Based on this case, we discuss how one should proceed in this disease. Primary renal plasmacytoma can be tentatively diagnosed preoperatively only in the presence of paraproteinemia or Bence-Jones proteinuria, as it cannot be distinguished from other renal tumors by imaging procedures. Postoperatively, further staging procedures must rule out bone involvement (solitary myeloma or multiple myeloma). Nephrectomy is required in patients with plasmacytoma only if renal complications occur.