Intracerebral Plasmacytoma in a Patient with HIV-1 Infection and SARS-CoV-2 Superinfection.

We present a rare case of intracranial solitary plasmacytoma arising in brain parenchyma in the basal nuclei. Clinical management and autopsy results of the case are described. Background: Intracranial plasmacytomas arising from brain parenchyma are extremely rare, and data from the literature are limited. Primary intracranial plasmacytomas are rare because plasma cells are not found in the brain in normal conditions. Commonly, intracranial plasmacytoma is associated with multiple myeloma, which is why multiple myeloma must be ruled out to diagnose solitary intracranial plasmacytoma. Considering that solitary plasmacytoma and multiple myeloma have some histopathological similarities, it is important to differentiate them because their respective treatments and prognoses are different. Imaging features of primary extramedullary plasmacytoma are nonspecific but are compatible with solid tumors with invariable enhancement. Plasmacytoma was aggressive because it was not diagnosed after the first MRI, but 1.5 months later, MRI showed a large object. We present a rare case of intracranial solitary plasmacytoma arising in brain parenchyma in the basal nuclei.