Based on the results of the renal biopsy, bone marrow biopsy, and lymph node biopsy, the correct diagnosis is CLL-associated monoclonal gammopathy of renal significance (MGRS).
The CLL was determined to be stage II according to the Rai system.
Renal biopsy findings: (A) The glomerulus showed segmental endothelial cell proliferation and swelling (periodic acid-silver methenamine, Masson staining, ×400). (B) Interlobular renal arteries showed intimal swelling and contained mainly lucent amorphous material with a mucoid appearance, which was classified as mucoid intimal hyperplasia. (C) Immunofluorescence staining showed C3 deposits in the mesangial area. The expansion of the lucent subendothelial zone of the glomerular capillary had dense deposition in the subendothelial and mesangial area. (D) Immunohistochemistry showed monotypic lymphocytes infiltrating the renal interstitium that were positive for CD20 and CD5.
References:
Hallek M, Cheson BD, Catovsky D, Caligaris-Cappio F, Dighiero G, Döhner H, et al. iwCLL guidelines for diagnosis, indications for treatment, response assessment, and supportive management of CLL. Blood 2018; 131(25):2745-2760.
Ma T, Wang H, Su T, Wang S. Case Report: Chronic Lymphocytic Leukemia With Recurrent Complement-Mediated Thrombotic Microangiopathy and C3 Glomerulonephritis. Front Med (Lausanne) 2022; 9:813439.
Strati P, Nasr SH, Leung N, Hanson CA, Chaffee KG, Schwager SM, et al. Renal complications in chronic lymphocytic leukemia and monoclonal B-cell lymphocytosis: the Mayo Clinic experience. Haematologica 2015; 100(9):1180-8.
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