Atypical presentation of a common opportunistic infection in advanced AIDS

Intracranial tuberculosis in immunocompromised patients can occasionally mimic central nervous system (CNS) neoplasms radiologically and complicate the decisions regarding management. A 42-year-old male presented with a history of fever and vomitings of 5 days duration. On evaluation he was found to be reactive for human immunodeficiency virus 1 infection with a CD4+ count of 63 cells/mm3 and a viral load of 1,260,779 copies /mL. He was started on highly active antiretroviral therapy with tenofovir, emtricitabine, efavirenz, Pneumocystis jiroveci prophylaxis and was discharged. After 5 months he developed aggressive behaviour, irrelevant talking and memory loss. On examination, he was irritable with memory disturbances; no focal neurological signs were evident. Magnetic resonance imaging brain and magnetic resonance spectroscopy (MRS) showed a large heterogeneous enhancing ill-defined lesion in the left parietooccipital lobe with a lipid lactate peak suggestive of infective aetiology. Cerebrospinal fluid (CSF) analysis showed glucose 33 mg/dL, protein 120 mg/dL, 40 cells/mm3 (all lymphocytes), adenosine deaminase 40U/L; Gram's stain was negative, Ziehl-Neelsen stain did not reveal acid-fast bacilli, toxoplasma, cryptococcal antigen tests were negative. Polymerase chain reaction for Epstein-Barr virus was also negative. In view of the clinical setting, CSF analysis supported by MRS findings he was started on antituberculosis treatment (ATT) and corticosteroids. Patient showed remarkable improvement clinically and radiologically with significant reduction in the size of the lesion. MRS is a useful non-invasive technique that can help in differentiating tuberculoma from lymphoma