case_images: PMC9098676_01
case_images: Timeline of symptoms, diagnostic approaches, and treatments of the patients. Abbreviations: sc., subcutaneous; iv.inf., intravenous infusion; CT, computer tomography; IFN-alpha, interferon alpha; R-Len, Rituximab-Lenalidomide; Pola-BR, polatuzumab vedotin-bendamustin-rituximab, Pola-R-GemOx, Polatuzumab vedotin-rituximab-gemcitabine-oxaliplatin (Created with BioRender.com).
case_images: pore-28-1610338-g001.jpg
case_images: PMC9098676_02_pore-28-1610338-g001.jpg
case_images: F1
case_images: No autopsy was performed (Figure 1, Patient 2).
case_images: PMC9098676_02
case_images: Timeline of symptoms, diagnostic approaches, and treatments of the patients. Abbreviations: sc., subcutaneous; iv.inf., intravenous infusion; CT, computer tomography; IFN-alpha, interferon alpha; R-Len, Rituximab-Lenalidomide; Pola-BR, polatuzumab vedotin-bendamustin-rituximab, Pola-R-GemOx, Polatuzumab vedotin-rituximab-gemcitabine-oxaliplatin (Created with BioRender.com).
case_images: pore-28-1610338-g001.jpg
case_images: PMC9098676_02_pore-28-1610338-g001.jpg
case_images: F1
case_images: No autopsy was performed (Figure 1, Patient 2).
case_images: Bone marrow trephine biopsy showing extensive marrow engagement by hairy cell leukemia with a predominantly interstitial pattern [(A):hematoxylin and eosin (H&E), x20 magnification], highlighted by CD20 (B) and BRAF (C) immunohistochemistry. Rectal resection biopsy showing large immunoblastic cells [(D):H&E, x20] with a dim CD20 expression (E) with strong expression of CD79a (F) and MUM1 (G). Cells lack CD10 expression (H).
case_images: pore-28-1610338-g002.jpg
case_images: PMC9098676_02_pore-28-1610338-g002.jpg
case_images: F2
case_images: The bone marrow trephine biopsy also confirmed the extensive marrow infiltration by hairy cell leukemia with a predominantly interstitial pattern (Figure 2A) proven by CD20 (Dako, Glostrup, Denmark) and BRAF (VE1, Ventana Medical Systems, Tucson, AZ) immunohistochemistry (Figures 2B,C). The cells displayed CD20 positivity, CD79a (Dako, Glostrup, Denmark) positivity with MUM1 (Dako, Glostrup, Denmark) expression lacking CD10 (Leica-NovoCastra, Newcastle, UK) expression (Figures 2D-H). No autopsy was performed (Figure 1, Patient 2).