Primary central nervous system lymphoma (PCNSL) is defined as lymphoma arising in the brain, spinal cord, or leptomeninges without prior or concurrent tumor outside the central nervous system (CNS). The patients with PCNSL may be immunocompetent or have immunocompromised status. The incidence of CNS lymphoma has increased in recent decades due to the increased number of immunocompromised patients (organ transplant recipients, HIV infection, etc.). PCNSL develops in 2% to 12% of AIDS patients. However, the incidence has decreased recently with the availability of highly effective anti-retroviral therapy. This autopsy specimen shows large hemorrhagic and necrotic lesions involving the white matter of bilateral parietal lobes in a HIV+ve patient. The morphologic and immunophenotypic findings on biopsy were diagnostic of diffuse large B-cell lymphoma. The patient succumbed to the tumor within 6 months after presentation despite chemotherapy and radiation.