I did some checking this morning. The trainers name is Voon Chong. His protrusion is called an osteoma and it is not rooted in the brain.
An osteoma is a benign (not cancerous) bony growth which can appear as a hard, fixed knot or bump on the forehead or scalp, though osteomas can sometimes develop within the sinuses as well. An osteoma of the forehead or scalp typically feels like a raised, solid bump which is firmly affixed to the underlying bone. While one can move or slide the skin and tissue over the bump, the osteoma itself cannot be moved or shifted. Osteomas usually develop slowly over time, and most commonly present in a person’s 20-40s. While they are most frequently solitary, it is not unusual for a patient to present with multiple osteomas. Usually asymptomatic (or not causing symptoms), osteomas rarely cause pain or discomfort and most commonly bother people by their appearance.