Gliomatosis cerebri: a brain tumour which is too difficult to treat?

Gliomatosis cerebri is a rare form of primary diffuse brain tumour first described by Nevin in 1938. It was originally considered to be a post-mortem diagnosis before Troost et al reported a clinically diagnosed case in 1987. However antemortem diagnosis remains difficult due to vague clinical symptoms and often non-specific findings on CT scanning. Gliomatosis cerebri has been classified by the World Health Organization as an infiltrative tumoural process, which involves at least two, and usually three, lobes of the brain. Magnetic resonance (MR) imaging shows a diffuse infiltrative process with possible mass effect but no necrosis. Histology is usually of a low grade astrocytic neoplasm which seemingly infiltrates out of proportion to the degree of anaplasia. We report two patients who presented over the past year, whose clinical and radiological features prompted a preoperative diagnosis of gliomatosis cerebri, confirmed by biopsy.