Extramedullary Plasmacytoma-like PTLD
Abstract and Introduction
Abstract
Most monomorphic posttransplantation lymphoproliferative disorders (PTLDs) resemble diffuse large B-cell lymphoma or Burkitt lymphoma. Rare cases of PTLD resembling extramedullary plasmacytomas have also been described. This report describes the clinical, histologic, phenotypic, and genotypic findings in 4 cases of plasmacytoma-like PTLD (2 nodal, 1 adenoidal, and 1 cutaneous) and compares the findings with extramedullary involvement by plasma cell neoplasms arising in immunocompetent patients. Plasmacytoma-like PTLDs characteristically arise late after transplantation (mean, 7.0 years), show a variable association with Epstein-Barr virus (2/4 cases positive), and demonstrate histologic and phenotypic findings that overlap with immunocompetent extramedullary plasma cell neoplasms. None of the patients with plasmacytoma-like PTLD developed lytic bone lesions, and 3 of 4 patients had complete responses (>2 years) to reduction of immunosuppression, confirming the role of immunosuppression in the pathogenesis of these lesions. This report, which represents the first case series of plasmacytoma-like PTLD, clarifies the features of this rare subtype of PTLD.
Introduction
Posttransplantation lymphoproliferative disorders (PTLDs) are a diverse group of lymphoid proliferations that arise secondary to immunosuppression in the setting of solid organ or bone marrow transplantation. Three primary categories are defined by the World Health Organization: "early lesions" composed of reactive plasmacytic hyperplasia and infectious mononucleosis–like proliferations, polymorphic PTLD, and monomorphic PTLD. The majority of PTLD cases are positive for Epstein-Barr virus (EBV), although EBV-negative PTLDs are increasingly recognized and may display distinct clinicopathologic features.
Most monomorphic PTLDs may be further classified as diffuse large B-cell lymphoma or Burkitt lymphoma. However, rare cases of monomorphic PTLDs resembling extramedullary plasmacytomas have also been reported. To date, the clinical and pathologic features of plasmacytoma-like PTLDs have been incompletely characterized. In this report, we describe the clinical, histologic, phenotypic, and genotypic findings in 4 cases of plasmacytoma-like PTLD and compare the findings with those seen in extramedullary involvement by plasma cell neoplasms (PCNs) arising in immunocompetent patients.