Renal intravascular large B-cell lymphoma predominantly localized in peritubular capillaries.

We report on a 70-year-old woman with intravascular large B-cell lymphoma, in whom the renal lesion was localized in the peritubular capillaries. The patient complained of fatigue, general malaise, and unsteadiness when walking. Laboratory tests showed anemia, increased C-reactive protein, and mild renal failure, with a serum creatinine level of 1.31 mg/dL and no remarkable proteinuria or hematuria. Renal biopsy showed intravascular large B-cell lymphoma. The large atypical cells were mainly accumulated within the peritubular capillaries and no large atypical cells were found in the glomeruli. Skin and bone marrow biopsies confirmed intravascular large B-cell lymphoma. Brain magnetic resonance imaging showed multiple small infarctions in the cerebral white matter. The patient was treated with dexamethasone, methotrexate, and cytarabine followed by CHOP (combined cyclophosphamide, doxorubicin, vincristine, and prednisone) and R-CHOP (CHOP with the recombinant anti-CD20 antibody rituximab), and her renal function improved soon after the start of chemotherapy.