Plasmablastic lymphoma versus anaplastic myeloma in a human immunodeficiency virus negative male: a diagnostic quandary.

We report a 45-year-old male presenting with an intraoral mass originating from the right maxillary alveolar ridge. Radiologic investigations revealed osteolytic lesions in the right maxilla, skull, and lumbar vertebrae. This finding led to further investigations like electrophoresis of serum proteins for M band, quantitative estimation of immunoglobulins, urine electrophoresis for monoclonal light chain, and bone marrow biopsy. All these findings were inconclusive. Incision biopsy revealed the features of plasmacytoma. Since the other reports were incongruent with the histopathology report, for establishing a diagnosis of plasmacytoma, Immunohistochemistry of the specimen was done which revealed it to be a case of plasmablastic plasma cell neoplasm favoring plasmablastic lymphoma. The diagnostic confusion which arose in this setting is discussed in details.