Diagnosis and Treatment of Plasmablastic Lymphoma in an Immunocompetent Patient: A Report of a Rare Case.

Plasmablastic lymphoma (PBL) is a rare and aggressive subtype of diffuse large B-cell lymphoma (DLBCL), often associated with immunodeficiency states such as HIV infection. However, PBL can also occur in HIV-negative individuals, where it exhibits diverse anatomical involvement and poorer prognosis. This case presents a 50-year-old HIV negative male patient with progressive lower limb weakness and numbness due to a thoracic paravertebral lesion extending from T1 to T6, causing compressive myelopathy. Imaging raised concerns for malignancy, and histopathology confirmed PBL with positivity on IHC for CD38, CD138, and Cyclin D1. Given its aggressive nature, early intervention was critical. The patient underwent surgical decompression via T2-T6 laminectomy followed by chemotherapy with the EPOCH regimen (etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin). After two cycles, significant symptomatic improvement was observed. HIV-negative PBL is associated with poor prognosis and high relapse rates, necessitating aggressive treatment and close monitoring. This case highlights the challenges in diagnosing and managing HIV-negative PBL, emphasizing the importance of multimodal treatment strategies, including surgical intervention, intensive chemotherapy, and follow-up.