An Atypical Presentation of an Uncommon Malignancy: Plasmablastic Lymphoma Presenting As Recurrent Scrotal Abscesses.

Plasmablastic lymphoma (PBL) is a rare and extremely diagnostically challenging entity. We report a unique case of PBL in an adult male with a history of recurrent scrotal abscesses who presented with progressively worsening scrotal pain, swelling, and drainage. Pelvic CT demonstrated a large scrotal abscess with external draining tracts with foci of air. Surgical debridement revealed necrotic tissue throughout the abscess cavity, abscess wall, and scrotal skin. Immunohistochemical analysis of the scrotal skin specimen uncovered diffuse proliferation of plasmacytoid cells with immunoblastic features that stained positive for CD138, CD38, IRF4/MUM1, CD45, lambda restriction, and Epstein-Barr encoded RNA in situ hybridization (EBER-ISH) with high Ki-67 proliferation index greater than 90%. Taken together, these findings confirmed a diagnosis of PBL. Treatment with six cycles of infusional etoposide, prednisolone, vincristine, cyclophosphamide, and hydroxydaunorubicin (EPOCH-like regimen) was administered with subsequent positron emission tomography (PET)/CT confirmation of complete response. There was no clinical evidence of lymphoma recurrence at the time of follow-up six months later. Our case exemplifies the growing diversity of ways in which PBL may manifest and underscores the importance of a clinician's familiarity with this entity and its well-defined risk factor of immunosuppression.