Central nervous system histoplasmosis in an immunocompetent 5-year-old patient: a case report

Case presentation: IL, 5 years old, female, weighing 28,5kg, previously healthy. Sought medical attention due to intense and progressive headache for a year, worsening in the previous 90 days, followed by vomiting. Cranial magnetic resonance showed an intraparenchymal lesion in the optic chiasm suggestive of inflammatory injury by infection or cancer, raising the hypothesis of tuberculosis and optic pathway glioma. Cerebrospinal fluid analysis was negative for tumor cells and Mycobacterium tuberculosis. Tuberculin tests and screening for HIV, hepatitis, cytomegalovirus, and syphilis were non-reactive. During hospitalization, presented with seizure, followed by persistent hyporesponsiveness, Glasgow Coma Scale (GCS) of 9. New neuroimaging showed an increase in the number of lesions diffusely in both hemispheres and in the meninges. In the third month of hospitalization, the patient evolved with complications, such as new seizures, repetitive respiratory infections, and a decrease in neurological state, GCS of 6–7. A biopsy of cerebral tissue showed the presence of Histoplasma capsulatum, giving the diagnosis of central nervous system histoplasmosis (CNS). Treatment with amphotericin B and itraconazole was established, both without improvement. The latest neuroimaging showed severe neurological sequelae, with lesions suggestive of granulomatous disease, ischemia, and gliosis/encephalomalacia. As the patient was stable, she was released for ambulatory treatment with itraconazole for a year. The family agreed to prioritize comfort above invasive measures, which would not bring benefits to the patient.

Discussion: Exposure to H. capsulatum is common for people in endemic areas, however, most are asymptomatic or exhibit few pulmonary symptoms. CNS involvement is uncommon in immunocompetent patients and its occurrence as the only manifestation is even rarer. CNS involvement occurs by hematogenous spread to the meninges or brain, with chronic meningitis being the most common manifestation. Treatment is difficult, and amphotericin B should be used as initial therapy in all patients, followed by an azole agent administered orally for an indefinite period.

Final comments: The clinical case reports an episode of histoplasmosis showing CNS involvement as the only manifestation of the disease in an immunocompetent pediatric patient. This type of manifestation is uncommon, making the diagnosis of the pathology and its early treatment even more challenging.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
18 September 2023