Gastric Collision Tumor of Adenocarcinoma and MALT Lymphoma: A Rare Coincidence or Proof of <i>H. pylori</i> Incrimination?

Abstract

Collision tumors of adenocarcinoma and MALT (Mucosa-associated lymphoid tissue) lymphoma are often rare findings of resection specimens of gastric carcinomas. The fact that these two histological lesions are contiguous may suggest a common oncogene. As it is widely known, Helicobacter pylori (H. pylori) plays a leading role in gastric oncogenesis. Could it be responsible for these tumors? As of today, the exact mechanism is still unclear. However, some histological findings may suggest that H. pylori promotes the formation of MALT lymphoma which increases the risk of carcinomatous changes. Prognosis of collision tumors is tightly linked to the carcinoma lesion, which is generally poor due to diagnostic delay. Large scale strategies to eradicate H. pylori and detect early lesions could reduce the mortality of this disease.