Tuberculous brain abscess mimicking stroke in HIV-negative patient

A 58-year-old male recycling worker was admitted to the emergency department with sudden-onset left-sided hemiparesis and altered mental status, prompting an initial evaluation for acute stroke. The patient also had a one-year history of progressive cognitive impairment, confusion, behavioral changes, and weight loss, with a BMI of 16.45 kg/m² upon admission. Brain magnetic resonance imaging revealed a large intraaxial expansile lesion centered in the right parietal lobe, predominantly cystic and necrotic in appearance, containing fuid-fuid levels and a diffusion restriction component in its posterior aspect, suggestive of an abscess (Fig. 1).

Fig. 1
Axial T2-weighted MRI (A) shows a lesion measuring 5.9 × 5.4 × 5.4 cm (CC × LL × AP) and exerts a compressive effect on the brain parenchyma, with hyperintense areas in the white matter secondary to vasogenic edema, accompanied by subfalcine herniation and right uncal herniation into the suprasellar cistern. There is an approximate 1.7 cm midline shift to the left. Peripheral rim enhancement without surrounding capsule irregularity is observed, findings that are suggestive of a tuberculous abscess rather than a pyogenic one. Sagittal MRI on T1 complements the visualization of the lesion (B).

Family members reported that the patient had been receiving treatment for pulmonary Tuberculosis (TB) for three months without adherence. A new chest CT scan was performed, which revealed pulmonary cavities with thickened walls in the apical-posterior segment of the left upper lobe and the superior segment of the left lower lobe. The smear of sputum microscopy was negative for acid-fast bacilli. HIV serology was negative.

The patient underwent abscess resection, revealed an encapsulated mass containing purulent material. Polymerase chain reaction analysis (GeneXpert) of the purulent fuid confrmed the presence of Mycobac-terium tuberculosis with no detected resistance to rifampin (Fig. 2).

Fig. 2
Photo from the surgery showing an encapsulated lesion, well-demarcated from the brain, with an abscess-like appearance.

Histopathological examination showed chronic granulomatous infammation with central necrosis. Treatment was initiated with rifampin, isoniazid, pyrazinamide, and ethambutol, in addition to dexamethasone due to perilesional edema.

Central Nervous System (CNS) TB is the most severe form of systemic TB due to its high mortality rate and potential for serious neurological complications, accounting for 2 %–5 % of TB cases¹. The most frequent manifestations are meningitis and tuberculome, meanwhile TB abscesses are present in only 10 % of these patients². Symptoms typically include headache, focal neurological defcits, and seizures³. Therefore, even in immunocompetent patients with pulmonary TB, CNS evaluation is crucial if neurological symptoms arise.

• Ethics approval statement
  We confrm that informed consent was obtained from the patient involved in this study. The patient provided written consent for the inclusion of their case details and any relevant information in the publication, in accordance with ethical and legal requirements. No artifcial intelligence tools were used for image generation or text development, ensuring full compliance with legal guidelines.
• Funding
  This study received no funding. The data were obtained from the medical records of a patient admitted to the Hospital de Clínicas de Porto Alegre.

Data availability

The data that support the fndings of this study are available from the corresponding author upon reasonable request.

References

• ¹ Torres C, Riascos R, Figueroa R, Gupta RK. Central nervous system tuberculosis. Top Magn Reson Imaging 2014;23:173–189.
• ² Bernaerts A, Vanhoenacker FM, Parizel PM, Van Goethem JWM, Van Altena R, Laridon A, et al. Tuberculosis of the central nervous system: overview of neuroradiological findings. Eur Radiol 2003;13:1876–1890.
• ³ Roopesh Kumar VR, Gundamaneni SK, Biswas R, Madhugiri VS. Tuberculous cerebellar abscess in immunocompetent individuals. BMJ Case Rep 2012;2012, bcr2012006984.

Edited by

• Editor:
  Dr. Luciano Goldani

Publication Dates

• Publication in this collection
  16 Mar 2026
• Date of issue
  2026

History

• Received
  21 July 2025
• Accepted
  07 Dec 2025
• Accepted
  12 Dec 2025