Tumour-like presentation of brainstem tuberculoma: a lesson learnt

Brainstem tuberculoma is diagnostically challenging as it lacks clinical clues and imaging mimics a high-grade glioma (HGG). We report the case of an adolescent girl diagnosed with brainstem HGG, who was referred to our centre for Gamma Knife. Initial MRI showed a pontomedullary junction, ring-enhancing lobulated lesion demonstrating distinct central hypointensity on T2-weighted (T2W) and fluid-attenuated inversion recovery (FLAIR) images with extensive vasogenic oedema. An alternative diagnosis of infection was entertained, and biopsy was suggested; however, the parents opted for a trial of alternative treatment. Suboccipital craniotomy and debulking were only performed 3 months later when her symptoms worsened, and MRI revealed enlargement of the lesion. A cheesy 'tumour' was noted intraoperatively; histopathological findings later confirmed chronic granulomatous inflammation. In an endemic area, a high index of suspicion of a tuberculoma is vital specifically in the presence of central T2W/FLAIR hypointensity of a ring-enhancing lesion.