Diagnostic panel of markers CD45, CD20, CD3, CD138, and CD56 for oral solitary plasmacytoma of bone

Abstract

Aim: The present case aims to emphasize on the role of immunophenotyping in plasmacytic malignancies. Introduction: Solitary plasmacytoma of bone (SPB) is a rare entity often encountered in vertebrae and less frequently in long bones. Its presence in jaws is extremely rare, accounting for 4.4% of cases only. About 5% of patients with plasma cell dyscrasias present with SPB. Case report: An elderly male patient reported with a chief complaint of growth in the anterior region of the lower jaw since 3 months. The histopathological features following an incisional biopsy were suggestive of pyogenic granuloma. Serological investigations revealed seropositivity for human immunodeficiency virus (HIV)-1 antibody with hypergamma-globulinemia and hypoalbuminemia. Histopathology of excisional biopsied tissue revealed a round cell malignancy with plasmacytic morphology. Further, to arrive at a specific final diagnosis, immunohistochemistry (IHC) was employed with a panel of markers CD45, CD20, CD3, CD138, and CD56. This panel enabled us to establish a final diagnosis of SPB with clinicopathologic correlation. Conclusion: The present case posed a diagnostic dilemma as it presented with overlapping features of non-Hodgkin’s lymphoma (NHL), multiple myeloma (MM), extramedullary plasmacytoma (EMP), and plasmablastic lymphoma (PBL). A thorough clinical, radiological, serological, and IHC panel helped to diagnose the present case. The CD56 enabled differentiation between SPB and PBL. Thereby, this article emphasizes on the need for a panel of IHC markers that permit definitive diagnosis of lymphopoietic malignancies. Clinical significance: Timely diagnosis of malignant lesions is an essential concern for effective management. Thus, we emphasize that the IHC is a valuable investigative tool in the diagnosis of round cell tumors with plasmacytoid morphology.