Original ArticlesBone Marrow Histopathology in the Diagnostic Evaluation of Splenic Marginal-zone and Splenic Diffuse Red Pulp Small B-cell Lymphoma A Reliable Substitute for Spleen Histopathology?Ponzoni, Maurilio MD*,†; Kanellis, George MD‡; Pouliou, Evi MD‡; Baliakas, Panagiotis MD§; Scarfò, Lydia MD∥; Ferreri, Andrés J.M. MD†,¶; Doglioni, Claudio MD*,†; Bikos, Vasilis MD§; Dagklis, Antonis MD∥; Anagnostopoulos, Achilles MD§; Ghia, Paolo MD†,∥; Stamatopoulos, Kostas MD§,#; Papadaki, Theodora MD‡Author Information *Pathology Unit †Unit of Lymphoid Malignancies ¶Medical Oncology Unit, Department of Oncology, San Raffaele Scientific Institute ∥Laboratory of B cell Neoplasia, Università Vita-Salute San Raffaele, Milan, Italy ‡Hematopathology Department, Evangelismos Hospital, Athens §Hematology Department-HCT Unit, G. Papanicolaou Hospital #Institute of Agrobiotechnology, Center for Research and Technology, Thessaloniki, Greece M.P., K.S., and T.P. designed the study, performed the research, analyzed data, and wrote the manuscript. E.P., C.D., L.S., A.J.M.F., and P.G. provided clinical samples. G.K., P.B., V.B., A.D., and A.A. analyzed the data. Conflicts of Interest and Source of Funding: Supported in part by the ENosAI project (code 09SYN-13-880), cofunded by the EU and the Hellenic General Secretariat for Research and Technology to K.S.; Cariplo Foundation (Milan, Italy) to P.G. and K.S.; Program Molecular Clinical Oncology-5 per mille number 9965 and Investigator Grant, Associazione Italiana per la Ricerca sul Cancro (AIRC—Milano, Italy) to P.G. and M.P. Correspondence: Maurilio Ponzoni, MD, Pathology Unit, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milano, Italy (e-mail: [email protected]). The American Journal of Surgical Pathology: November 2012 - Volume 36 - Issue 11 - p 1609-1618 doi: 10.1097/PAS.0b013e318271243d Buy Metrics Abstract Primary splenic small B-cell lymphomas mostly comprise the distinct entity of splenic marginal-zone lymphoma (SMZL) and the provisional category of splenic lymphoma/leukemia unclassifiable, mainly represented by the hairy cell leukemia variant and splenic diffuse red pulp small B-cell lymphoma (SDRL). Until recently, histopathologic examination of splenectomy specimens was considered mandatory for the diagnosis of SMZL. However, nowadays, mainly because of advances in chemoimmunotherapy, splenectomy is performed much less frequently. We evaluated the diagnostic efficacy of bone marrow biopsy (BMB) histopathology in the diagnostic approach toward SMZL and SDRL and tested whether it may serve as a substitute for spleen histopathology in the differential diagnosis between these 2 entities. To this end, we conducted a paired assessment of BMB and spleen diagnostic samples from 46 cases with a diagnosis of SMZL (n=32) or SDRL (n=14) based on spleen histopathology. We demonstrate that detailed immunohistopathologic BMB evaluation offers adequate evidence for the confirmation of these entities and their differential diagnosis from other small B-cell lymphoma histotypes. Notably, the immunophenotypical profile of SMZL and SDRL was identical in both BMB and spleen specimens for 21 evaluated markers. Paired assessment of BMB and spleen specimens did not identify discriminating patterns of BMB infiltration, cytology, and/or immunohistology between SMZL and SDRL. Accordingly, bone marrow histopathology contributes significantly in confirming the diagnosis of SMZL and SDRL. However, presently it is not possible to distinguish SMZL from SDRL on the basis of BMB evaluation alone; hence, histopathologic examination of the spleen remains the “gold standard” approach. © 2012 Lippincott Williams & Wilkins, Inc.