Synchronous occurrence of gastric adenocarcinoma and MALT-type lymphoma: A case report and literature review

The coexistence of multiple primary malignant tumors in an organ is rare. This includes the extremely rarely reported combination of gastric adenocarcinoma and gastric MALT-type lymphoma as synchronous tumors. We describe a case of a 72-year-old man diagnosed with this combination. He had no remarkable medical history and came to our hospital because of discomfort in the gastric area. Although the biopsy revealed adenocarcinoma only, the microscopic findings after partial gastrectomy incidentally showed additional lymphoma that was subsequently confirmed by immunohistochemistry as MALT-type lymphoma. This case study and literature analysis aims to raise awareness of the possibility of synchronous malignant neoplasm in the stomach to enhance preoperative diagnosis.