EP451 - Lymphoma of the Anus and Rectum in HIV+ Patients: A Case Report

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Purpose/Background: Lymphoma is a serious complication from HIV infection. The gastrointestinal tract accounts for the major extranodal site of lymphoma in HIV+ patients. These malignancies commonly afflict the stomach and cecum. In this case report, we present two cases of lymphoma in the anus and rectum in HIV+ patients.

Methods/Interventions: Two cases of anorectal lymphoma were identified in HIV+ patients that co-presented with anal dysplasia

Results/Outcomes: The first patient, a 36 year old HIV+ male, presented to the colorectal clinic in October 2022 with a chief complaint of anal discharge. This patient had a 20 year history of HIV on antiretroviral therapy with a recent CD4 count of 300. On digital rectal exam, the patient was found to have an anal fistula and a rectal mass. The patient subsequently underwent three EUAs with nondiagnostic biopsies of the mass and AIN2. Pelvic CT and MRI demonstrated a rectal mass with infiltration of the perirectal fat and pelvic lymph node involvement. The patient then underwent IR guided biopsy of perirectal lymph nodes which demonstrated abnormal lymphoid tissue that stained positive for EBV and markers of Hodgkin’s lymphoma. This patient was referred to hematology for additional management. The patient has since undergone chemotherapy with ABVD combination therapy. The patient has since had radiographic decrease in tumor and lymph node size and now undergoes routine surveillance imaging. The second patient, a 37 year old HIV+ male, presented to the colorectal clinic in July 2024 with anal pain and bleeding. The patient had a history of HIV and started antiretroviral therapy within the last year, with a most recent CD4 count of 58 in March 2024. On digital rectal exam, the anus exhibited diffuse nodularity and stenosis. The patient subsequently underwent an EUA in August 2024 where a biopsy was taken of nodularity noted on the anterior aspect of the anus. The final pathology of this specimen demonstrated that the nodularity was composed of lymphoid tissue of B-cell origin that stained positive for c-myc and EBV. The specimen additionally demonstrated an area of AIN 3. The patient then underwent an MRI of the pelvis, PET scan, and was referred to hematology for further treatment.

Conclusion/Discussion: These cases of lymphoma are rare presentations of HIV associated lymphoma in the gastrointestinal tract, as the anus and rectum are exceedingly rare sites of primary lymphoma development. HIV+ patients are at an increased risk of anal cancer compared to their non HIV+ counterparts, but these tumors are primarily squamous cell in origin, not lymphoid. Both patients were HIV, EBV, and HPV positive, presenting with both lymphoma of the anus and advanced anal intraepithelial lesions. As the anus is a rare site for lymphoma to present in HIV+ patients, this unique presentation may be due to co-infection with HIV, EBV, and HPV. We hope to highlight this uncommon presentation of HIV associated lymphoma and bring awareness to this unique co-presentation with HPV related dysplasia of the anus. Lymphoma should remain on the differential when evaluating an anal or rectal mass and may require a deeper biopsy when initial biopsies are nondiagnostic.