Dr JESSICA OON1, DR PETER KOLOVOS1, DR MAN-YUK HO1, DR ANGELA BAYLYL2, DR JOHN GIANNOUTSOS1, DR BHADRAN BOSE1
1Nepean Hospital, Penrith, Australia, 2Westmead Hospital , Westmead, Australia
Biography:
Dr Jessica Oon is a Basic Physician Trainee at Nepean Hospital keen on pursuing Nephrology training.
Background:
Lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (WM) is a low-grade non-Hodgkin’s lymphoma characterised by lymphoplasmacytic bone marrow infiltration with an IgM paraprotein. Renal complications of WM are rare. We discuss a case of nephrotic syndrome and biopsy-confirmed minimal change disease (MCD) leading to the eventual WM diagnosis.
Case Report:
A 52-year-old male presented with one week of progressive dyspnea and pedal oedema. He examined hypertensive (blood pressure: 147/93mmHg) and hypoxic (95% on 2L nasal prongs) with signs of anasarca. He had no known medical or surgical co-morbidities.
Serum studies reported a creatinine of 79umol/L, hypoalbuminemia (albumin: 23 g/L) and kappa-restricted IgM paraproteinemia (kappa paraprotein: 10g/L IgM; peripheral light chain ratio kappa/ lambda: 1.8). Urine studies reported nephrotic range proteinuria (protein/creatinine ratio: 526 mg/ mmol, albumin/creatinine ratio: 473 mg/mmol), with no microscopic haematuria. The salient findings from CT and PET were bilateral widespread mediastinal and axillary lymphadenopathy, a 96x43x108mm mesenteric mass, an 83x25x31mm pelvic mass, and increased diffused bone marrow activity. On kidney biopsy, there was kappa-restricted light chain deposition and glomerular IgM-related lymphocytic infiltration on immunofluorescence and diffused podocytopathy secondary to MCD on electron microscopy. Cervical chain lymph node biopsy, bone marrow biopsy, and genetic testing supported a MYD88-mutated monoclonal B cell lymphoproliferative pathology with kappa light chain restriction involving the lymph nodes and bone marrow, confirming WM.
With WM and MCD established, treatment was initiated with prednisone, Rituximab, and Bendamustine. This improved serum albumin and urine albumin/creatinine ratio and reduced the widespread lymphadenopathy and soft tissue mesenteric mass.
Conclusions:
WM with renal involvement is uncommon. However, our case emphasises the imperative need for screening for secondary causes of MCD, especially haematological malignancies.