Aberrant acquisition of T-cell associated markers in plasma cell neoplasms: An aggressive disease with extramedullary involvement and very short survival

Abstract

Background: Plasma cell neoplasms can show aberrant expression of a different lineage-related antigens, however, co-expression of T-cell associated markers on malignant plasma cells is extremely rare. Material and methods: This is a report of clinicopathologic characteristics of three myeloma patients with emergent plasmablastic morphology and aberrant acquisition of T‐cell associated markers. An extensive literature search for similar cases was conducted and the relevant pathologic, clinical and prognostic characteristics were summarized. Results: A total of 22 cases of plasma cell neoplasm, showed aberrant co-expression of T-cell markers. We found an evident association between aberrant expression of T-cell markers on malignant plasma cells and extramedullary involvement, aggressive morphologic features, high proliferative index ki67 >90%, aggressive clinical course, adverse outcome with short survival. Conclusion: Due to rarity of this aberrant phenotype and scarcity of the published data, the precise causative mechanism and its clinical implications have not yet been elucidated.