An atypical case of neurotoxoplasmosis in immunocompetent patient

Toxoplasmosis is an infection caused by Toxoplasma gondii, an intracellular protozoan that is often associated with immunocompromised patients and is rare in immunocompetent. A 60-year-old man was admitted with a history of 2 days of headache and right-sided weakness. There was no history of fever, surgeries, or any other comorbid illness. Cerebrospinal fluid showed just mild pleocytosis with 15 cells/mm³, predominantly lymphomononuclear. MRI showed Peripheral enhancing lesion with central diffusion restriction and perivascular enhancing lesion with restricted diffusion with vasogenic edema and leptomeningeal enhancement in the white matter. Viral serologies, tumor markers, protein electrophoresis were normal. The patient was submitted to brain biopsy, revealing necrotic brain parenchyma with predominantly acute inflammation, with diffuse encephalitis pattern, and cysts with bradyzoites (cystozoites) of Toxoplasma gondii in the brain parenchyma. The central nervous system infection by Toxoplasma gondii can present as meningoencephalitis during primary infection in an immunocompetent, although it is rare. Central nervous system lymphoma is the main differential diagnosis of neurotoxoplasmosis by imaging, especially in our case.