Cerebral lymphoma mimicking glioblastoma in an AIDS patient / Linfoma cerebral que imita o glioblastoma em um paciente com AIDS

A 42-year-old male, HIV (human immunodeficiency virus) positive for 13 years, but without use of antiviral therapy, presented weight loss of 6 kg and erythematous-purplish lesions in the right buttock. Biopsy was showed cutaneous diffuse large B-cell lymphoma.  The patient received antiretroviral therapy and six cycles of chemotherapy achieving complete remission.After 5 years, the patient presented progressive headache with an episode of loss of balance with fall and mental confusion. Brain magnetic resonance imaging (MRI) showed a mass lesion in the periventricular region, involving the splenium of the corpus callosum with restricted diffusion. The brain images were consistent with glioblastoma (GBM) or DLBCL (diffuse large B-cell lymphoma). The hypoperfusion of the lesion on MRI was of fundamental importance for the differential diagnosis, favouring the diagnosis of  DLBCL