Metastatic carcinoma: an unusual cause of focal brain lesions in HIV infection.

The most common causes of focal brain lesions (FBLs) in patients with HIV infection are cerebral toxoplasmosis, primary central nervous system lymphoma (PCNSL), and progressive multifocal leukoencephalopathy. Neoplasms other than PCNSL are uncommon. We report a rare case of metastatic carcinoma causing an FBL in a patient with HIV infection. The diagnostic workup and further management of FBLs in HIV are outlined in this review. The standard approach includes a lumbar puncture and cerebrospinal fluid (CSF) analysis for cytology and Epstein-Barr virus (EBV) DNA testing by polymerase chain reaction. Empiric therapy for PCNSL is justifiable for patients with positive CSF EBV-DNA test results and a positive single-photon emission computed tomography (SPECT) scan, especially if there has been no response to antitoxoplasmosis therapy. Brain biopsy may be indicated, however, in select cases that do not meet these criteria in order to identify potentially treatable infections and PCNSL.