Imaging of tuberculosis. III. Tuberculosis as a mimicker of brain tumour

To show that intracranial tuberculosis (TB) often masquerades as brain tumour.

Forty-six patients with intracranial TB, who after CT at the local hospital were referred for surgery or radiotherapy of brain tumour, are presented. Sometimes the correct diagnosis was first established during surgery for brain tumour.

The differentiation between TB and gliomas, meningiomas, metastases, or lymphomas may be impossible from the clinical history and CT findings. Angiography, done in 25 of our cases, often helped by not showing the expected tumour vasculature. MR, performed in 9 patients, helped by demonstrating a layered capsule on T2-weighted images in 4 of the lesions (hypointense rim outside hyperintense rim); the centres of the lesions were of decreased, usually very mixed T2 signal intensity.

Even in patients with findings typical of brain tumour, TB remains an important differential diagnosis.