From CCU to infectious disease ward: HIV-associated high-grade follicular lymphoma presenting with pulmonary thromboembolism and necrotizing pneumonia

Human immunodeficiency virus (HIV) infection is linked to a higher risk of venous thromboembolism (VTE) and lymphoproliferative disorders. The simultaneous occurrence of pulmonary thromboembolism (PTE), necrotizing pneumonia, and a newly diagnosed HIV-associated lymphoma is rare and presents diagnostic challenges. A 47-year-old male patient presented to the emergency department with acute chest pain and a brief episode of transient loss of consciousness. He also reported persistent lower back pain radiating to both knees and a 2-month history of progressive fatigue. Computed tomography (CT) pulmonary angiography demonstrated bilateral PTE with evidence of right ventricular strain. Systemic thrombolytic therapy was administered, followed by therapeutic anticoagulation. Subsequent chest CT imaging revealed necrotizing pneumonia with associated pleural empyema; hence, broad-spectrum IV antibiotics were promptly initiated. Further diagnostic evaluation identified necrotic paraaortic lymphadenopathy causing compression of the inferior vena cava with associated thrombosis. An excisional lymph node biopsy was performed after a non-diagnostic needle biopsy. Histopathological and immunohistochemical (IHC) analyses ultimately confirmed an unusual variant of Grade 3A follicular lymphoma. During further evaluation, the patient was also diagnosed with HIV infection, prompting the initiation of combination antiretroviral therapy (ART). In addition, an appropriate systemic chemotherapy regimen tailored to high-grade B-cell lymphoma was commenced. The patient was managed with close monitoring for treatment response and potential complications. This case emphasizes the complex prothrombotic state seen in HIV infection and the unusual presentation of HIV-associated lymphoma. Recognizing underlying immunodeficiency early is crucial for patients who present with unexplained thrombosis and necrotic lymphadenopathy.