RESUMO
Minimal change disease (MCD) in association with low-grade extra-nodal marginal zone B-cell lymphoma (MZL) of mucosa-associated lymphoid tissue (MALT) (MALT lymphoma) is a rare clinicopathologic entity. We report a 68-year-old male who presented with nephrotic range proteinuria as the first manifestation of underlying MZL, confirmed with standard set of investigations. Being a steroid non-responder, he was treated with rituximab demonstrating a marked response with resolution of proteinuria. However, he relapsed after 3 months. Upon relapse, a combination of rituximab and bendamustine (R-Benda) was initiated achieving sustained resolution of proteinuria. No additional treatment was administered and the proteinuria has remained in remission for over a year.
Assuntos
Linfoma de Zona Marginal Tipo Células B/diagnóstico , Nefrose Lipoide/diagnóstico , Adenocarcinoma/diagnóstico , Idoso , Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Antineoplásicos Alquilantes/administração & dosagem , Antineoplásicos Alquilantes/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cloridrato de Bendamustina/administração & dosagem , Cloridrato de Bendamustina/uso terapêutico , Neoplasias do Colo/diagnóstico , Diagnóstico Diferencial , Humanos , Linfoma de Zona Marginal Tipo Células B/tratamento farmacológico , Masculino , Recidiva Local de Neoplasia/patologia , Segunda Neoplasia Primária/diagnóstico , Proteinúria/diagnóstico , Rituximab/administração & dosagem , Rituximab/uso terapêuticoRESUMO
A direct role for BK polyomavirus infection in malignant tumors of renal allografts and urinary tract is emerging. Case reports suggest a link between BK virus (BKV) reactivation and development of malignancy in renal allograft recipients. Herein we describe the first case of BKV positive invasive urothelial carcinoma within the renal allograft, presenting with chronic diarrhea and weight loss 5 years following resolution of BK viremia/nephropathy (BKVN). Unique to our case was the remote history of BK viremia/BKVN, rising titer of anti-HLA antibody and presence of renal limited urothelial carcinoma with microinvasion of malignant cells staining positive for SV40 large T antigen (T-Ag). These findings suggest that persistence of subclinical BKV infection within the renal allograft may play a role in the malignant transformation of epithelial cells. Patients with history of BKVN may be at risk for kidney and urinary tract malignancy despite resolution of BK viremia/BKVN.
