case_images: PMC8259465_01
case_images: Plasmablastic lymphoma of the bladder. A: Transurethral bladder resection specimen. Intact urothelial mucosa with underlying hypercellular tumor infiltrating muscularis propria (H & E, x 10). B: Large plasmablastic cells with prominent eosinophilic nucleoli present in sheets, with frequent apoptotic bodies and mitotic figures (H & E, x 100). C: CD138 is expressed in lymphoma cells as well as the benign urothelial surface (x 10). Tumor cell stain diffusely positive for kappa, negative for lambda (inset, both x 100). D: Ki 67 demonstrated very high proliferation index approaching 100% (x 10).
case_images: CNCS-9-072-01.jpg
case_images: PMC8259465_01_CNCS-9-072-01.jpg
case_images: Figure1
case_images: Bladder biopsy revealed high-grade plasmablastic lymphoma (Figure 1).
case_images: Kidney biopsy with focal atypical kappa-restricted casts with acute tubular injury and patchy interstitial inflammation and edema, suggestive of kappa light chain cast nephropathy. A: Low power view shows renal cortex with focal large fractured casts (far left on tissue edge) and interstitial expansion by edema and mononuclear leukocytes. A glomerulus appears unremarkable (H & E, x 100). B. A representative glomerulus is normal in size and cellularity, with no evidence of focal segmental sclerosis or collapsing glomerulopathy typical of HIV-associated nephropathy (Periodic-acid Schiff (PAS), x 600). C: A fractured PAS-negative cast with angulated contours and adherent mononuclear leukocytes is shown (PAS, x 600). D: Some of the atypical casts are polychromatic (staining trichrome-red and blue), associated with interstitial inflammation and edema. Tubular atrophy and interstitial fibrosis occupied ~ 10 - 15% of the cortex. (Masson trichrome, x 400). E: Immunofluorescence stain of a fractured crystalline cast is strongly positive for kappa light chain (immunofluorescence, x 600). F: The casts stain negative for lambda light chain (immunofluorescence, x 400).
case_images: CNCS-9-072-02.jpg
case_images: PMC8259465_01_CNCS-9-072-02.jpg
case_images: Figure2
case_images: Diagnostic kidney biopsy, performed 9 days after presentation, revealed focal atypical kappa-restricted tubular casts with diffuse acute tubular injury and 30% interstitial inflammation and edema, consistent with kappa light chain cast nephropathy (Figure 2).