Colloid cysts are most effectively removed through a craniotomy, where part of the skull is removed to access the brain. It is a rare kind of brain tumour but one which is fortunately benign, meaning non-cancerous, carrying a mortality rate of 1.2 per cent.

Davina McCall has undergone brain surgery for a non-cancerous tumour, she revealed today. In a video posted on Instagram, the television presenter explained that a private health check – that she expected to “ace” – showed she had a colloid cyst. “It needs to come out because if it grows, it would be bad,” the 57-year-old said.

A brain tumour expert said that although they are not cancerous, colloid cysts can require major surgical intervention.