RESUMEN
We present a patient who underwent allogeneic peripheral stem cell transplantation (PSCT) for chronic myelocytic leukemia. Twenty months after the PSCT he experienced status epilepticus. Magnetic resonance imaging (MRI) revealed a focus in the ventral thalamus-hypothalamus region. Using stereotactic biopsy with histology and specific polymerase chain reaction investigation from brain tissue, cerebral toxoplasmosis was diagnosed and treated with antiparasitic therapy. Early recognition of such serious and potentially lethal disease enabled prompt specific treatment. This case report emphasizes the role of stereotactic biopsy in diagnosis of cerebral toxoplasmosis. Other methods such as MRI are non-invasive but not sufficiently specific and sensitive.