Synchronous gastric adenocarcinoma and MALT lymphoma in a patient with H. pylori infection. Could the two neoplasms share a common pathogenesis?

Low-grade primary MALT (mucosa-associated lymphoid tissue) lymphoma of the stomach is a neoplasm with an indolent course and a good prognosis. Patients with this type of neoplasm seem to have a higher risk for other neoplasms. Of interest is the association of gastric MALT lymphoma with gastric adenocarcinoma of intestinal type. We report the case of a patient, with a history of H. pylori-related gastritis, in whom a diagnosis of synchronous gastric adenocarcinoma of intestinal type and low-grade MALT lymphoma, occurring as collision tumors, was made. The stage procedures confirmed the presence of a locally advanced gastric tumor staged as T3 N1. The patient underwent two cycles of neoadjuvant EEP (etoposide, epirubicin, cisplatin) chemotherapy. After 2 months, a R0 total gastrectomy with D2-lymphoadenectomy was successfully performed. The development of simultaneous primary gastric lymphoma and carcinoma is a rare event. The possible coexistence of both tumors should be kept in mind, especially in patients infected with H. pylori, since a possible etiopathogenetic role of this bacterium has been differently postulated for both disease.