B-cell lymphoma with intracellular crystals: a mimic of crystal-storing histiocytosis

A 74-year-old man with chronic kidney disease and splenic marginal zone lymphoma, diagnosed 3 years ago, status post bendamustine and rituximab and now on zanubrutinib due to recurrence, presented with acute kidney injury and proteinuria. On admission, he had a serum creatinine level of 2.7 mg/dl (baseline, ≈1.9 mg/dl), a urine protein-to-creatinine ratio of 5 g/g, and a serum albumin level of 3.2 g/dl. Serum protein electrophoresis showed IgGκ M protein. Serum free light chain ratio was 3.2.
Source: Kidney International - Category: Urology & Nephrology Authors: Tags: Nephrology Image Source Type: research