Abstract
Ring-enhancing lesions are typically observed in patients with immunosuppression caused by underlying conditions such as HIV/AIDS or cancer. These lesions can arise from various etiologies, including infections, neoplasms, or vascular conditions. This case involves a male in his 30s from South America who presented to the emergency department after experiencing a seizure episode. He had no significant prior medical history and reported that he had not seen a doctor since childhood. A comprehensive workup was initiated during his hospitalization, including brain imaging that revealed a solitary ring-enhancing lesion. The evaluation encompassed brain CT and MRI, along with infectious labs measuring inflammatory and serological markers for several diseases. An infectious disease consultant was engaged to assist in developing a thorough assessment and management plan. Throughout the hospitalization, the patient exhibited a benign physical exam with no neurological deficits, remained afebrile, and displayed insignificant white blood cell counts and negative blood cultures. Serological test results were all negative for HIV, rapid plasma reagin, and tuberculosis, except for a positive Toxoplasma gondii IgG antibody level. This case is noteworthy because the patient presented with a solitary ring-enhancing lesion in the brain resulting from a prior T. gondii infection, despite the absence of documented risk factors for this condition.