A Rare Case of HIV-Associated Plasmablastic Lymphoma of Anal Canal.

Plasmablastic lymphoma, an acquired immunodeficiency syndrome defining malignancy, is a subtype of diffuse large B-cell lymphoma. It is classically described in the oral cavity, the extraoral presentation being rare. Owing to its rarity and aggressiveness, plasmablastic lymphoma poses a diagnostic and therapeutic challenge to the treating physician. A 40-year-old male, recently diagnosed with HIV infection, presented with bleeding per rectum and spurious diarrhea. Examination revealed proliferative growth in the anal canal. Biopsy of the lesion was diagnostic of plasmablastic lymphoma. Computed tomography and magnetic resonance imaging were done to stage the lesion and assess the local extent, respectively. A multidisciplinary board discussion was done, and the patient was instituted on antiretroviral therapy and chemoradiotherapy. Following six cycles of chemotherapy and 25 fractions of radiotherapy, he achieved complete remission.