La biopsia stereotassica nella diagnosi delle lesioni cerebrali focali nel paziente HIV-sieropositivo

HIV infection, especially in the advanced stages of the disease, predisposes patients to neurological disease which has a major impact on quality of life, prognosis and diagnostic and therapeutic requirements. Although highly active antiretroviral therapy (HAART) has limited the cases of severe immunodeficiency, opportunistic CNS infections (primary and secondary lymphomas, abscess from Toxoplasma gondii, Aspergillus spp., Candida spp., Cryptococcus neoformans, mycobacteria and progressive multifocal leukoencephalitis) are common in patients who have never received appropriate treatment. However, clinical, neuroradiological and serologic findings do not establish certain diagnosis leading to specific therapy in many patients. In our experience stereotactic biopsy is a safe and relatively simple technique for aspiration biopsy of brain tissue specimens for histological, microbiological and molecular investigations. From 1988 to date our hospital has performed stereotactic biopsy in 14 HIV-positive patients with cell-mediated immunodeficiency anti one or more brain lesions of doubtful nature giving rise to severe neurological symptoms. All specimens were sent to the pathological anatomy service for histological testing and the bacteriology and mycology laboratory to search for mycobacteria, moulds and yeasts likely to cause focal brain lesions. Histological diagnosis was primary brain lymphoma in seven cases, progressive multifocal leukencephalitis in two, HIV encephalitis in two, unspecified vasculitis in one and abscess from Aspergillus fumigatus in one. Material obtained in one case was not diagnostic due to haemorrhage. The procedure was well-tolerated by all patients who reported only mild headache on the days after biopsy. Survival after biopsy was six months on average; death was not related to the procedure in any case. When an effective therapy could be administered combined with immune replacement by antiretroviral therapy lesions regressed with a gradual disappearance of clinical symptoms. In conclusion, stereotactice biopsy is an effective, safe and useful procedure recommended for final diagnosis of focal brain lesions. Ethical doubts over performing this procedure in critically ill patients such as HIV-positive cases with advanced disease, were resolved considering the benefits offered by highly active antiretroviral therapy.