Bilateral lesions in the basal ganglia of a patient with acquired immunodeficiency syndrome.

Diagnosis: Cryptococcal gelatinous pseudocysts with meningitis. In patients with AIDS who have cerebral mass lesions, diagnoses of toxoplasmosis and lymphoma should always be considered. However, these lesions usually show contrast enhancement and edema [1], which was not the case for our patient. Furthermore, our patient was Toxoplasma seronegative, and the results of PCR of CSF specimens for Toxoplasma DNA were also negative [2]. Brain thallium-201 single-photon emissi n CT did not reveal abnormal accumulation in these lesions [3]. If these findings are taken together, cerebral toxoplasmosis and lymphoma are not likely diagnoses. Cryptococcosis in the CNS is the third-most frequent neurological complication in patients with AIDS [4], and it usually presents as sole meningitis without cerebral focal lesions [5]. However, cerebral focal lesions can also develop [6]. These