tuberculoma

Tuberculoma is a localized granulomatous lesion in the central nervous system caused by Mycobacterium tuberculosis. It most commonly involves the brain, where it presents as solitary or multiple intraparenchymal masses, and less often as spinal cord lesions. It represents a CNS manifestation of tuberculosis and may occur with or without meningitis.

Pathology: The lesion consists of organized granulomatous inflammation with caseous necrosis surrounded by a capsule of astroglial tissue; histology shows granulomas with Langhans giant cells. The lesion may be solid or contain caseous necrosis.

Clinical features: Symptoms reflect mass effect and inflammation, including headaches, focal neurologic deficits, seizures, or signs of raised intracranial pressure; systemic TB symptoms may be absent. Spinal tuberculoma can cause radicular pain or myelopathy.

Diagnosis: MRI is the key imaging modality; tuberculomas may enhance with contrast in a ring or solid pattern and are often surrounded by edema. They can be indistinguishable from neoplasms. Diffusion-weighted imaging helps differentiate a tuberculous abscess (restricted diffusion) from non-abscess tuberculomas. CSF analysis is helpful if meningitis is present. Microbiologic confirmation can be difficult; biopsy or excision yields histology and organisms. Tuberculosis screening (TST/IGRA) and systemic imaging for TB focus are used.

Treatment: Standard anti-tuberculous therapy is used, typically for 9–12 months or longer, consisting of isoniazid, rifampin, pyrazinamide, and ethambutol, with adjustments for drug resistance. Adjunctive corticosteroids are used to reduce edema. Surgical resection may be considered for diagnostic uncertainty or mass effect not responsive to medical therapy, or if there is a solitary accessible lesion.

Prognosis: With treatment, many lesions shrink and symptoms improve; deficits depend on location and duration. Differential includes glioma, metastasis, bacterial abscess, and fungal granulomas.