Acute Presentation of Primary CNS Lymphoma Mimicking Toxoplasma in HIV Infection.

Primary CNS lymphoma (PCNSL) accounts for up to 15% of non-Hodgkin lymphomas in HIV patients and is the second most common cause of space-occupying brain lesions in HIV patients after CNS toxoplasmosis. Differentiation of PCNL and CNS toxoplasmosis is crucial as PCNL carries a poor prognosis with survival time of 2-4 months without treatment but can be improved with prompt initiation of chemotherapy. These two entities often present clinically in a similar manner, and conventional imaging can also be a diagnostic challenge due to overlapping imaging characteristics. Thus, definitive diagnosis of PCNSL relies on histopathologic confirmation. Here, we present a case of intracranial lesion that presented acutely in the context of headache and left sided body weakness and was found to have PCNSL.