Disseminated nocardiosis in a patient with AIDS and B-cell non-Hodgkin's lymphoma: a case report.

Background: Disseminated nocardiosis is a rare and potentially fatal disease, with a higher incidence in immunocompromised patients, such as those living with human immunodeficiency virus (HIV) or hematological malignancies, including lymphoma. Information on Nocardia spp. infection in Venezuela is limited.

Case presentation: We present the case of a 62-year-old male patient, recently diagnosed with HIV, who exhibited prolonged fever and unintentional weight loss. Paraclinical tests revealed pancytopenia and a marked elevation of lactate dehydrogenase. Disseminated histoplasmosis was suspected, prompting a bone marrow (BM) aspirate. Culture and molecular studies for Histoplasma spp. and Mycobacterium tuberculosis in BM samples were negative. Antiretroviral therapy with tenofovir/lamivudine/dolutegravir was initiated, but the patient subsequently experienced clinical deterioration, including ascites, pericardial effusion, and respiratory failure. Post-mortem biopsy and immunohistochemistry identified non-Hodgkin's lymphoma of B-cell lineage, and mycological culture of BM isolated Nocardia farcinica.

Conclusion: Disseminated nocardiosis may mimic histoplasmosis. Nocardia spp. infection should be considered in HIV patients, particularly in advanced stages of infection.