Lymphoma of the stomach accounts for 2–5% of all gastric neoplasms. In general they are of B cell origin although T cell lymphomas do occur. The commonest gastric lymphoma arises from mucosa associated lymphoid tissue (MALT) rather than lymph nodes. The occurrence of MALT in the stomach is thought to be a response to chronic inflammation most frequently occurring as a result of H. pylori infection.
There is no longer any doubt that H. pylori is a very important cause of gastric lymphoma. B cell lymphomas of the stomach can be classified as either low grade or high grade depending upon their histological characteristics. Following diagnosis patients with gastric lymphoma should be appropriately staged with a combination of CT scan and endoscopic ultrasound. The treatment of low grade MALT lymphoma is eradication of Helicobacter infection if present. This results in tumour resolution in 70–100% of cases. Treatment of those patients who do not respond or those with highgrade tumours is with chemoradiotherapy. Surgery is generally reserved for the treatment of tumour or treatment related complications such as haemorrhage or bleeding.