Leiomyomas and Schwannomas

• Gastric leiomyomas originate from the muscular propria or lamina muscularis mucosae of the stomach
• Schwannomas are derived from Schwann cells of the peripheral nerves in the stomach

Gastro-intestinal stromal tumours (GISTs)

• Submucosal tumours which arise on the outside of the stomach
• Cell of origin - interstitial cell of Cajal
• Contain spindle cells
• 85% of GISTs have mutations in the C-KIT gene (a tyrosine kinase) - TK inhibitors effective in treatment