Collision tumour of the stomach with a cancer to cancer metastasis: a case report

INTRODUCTION: Coexistence of a primary gastric lymphoma and a gastric adenocarcinoma is a rare event. The diagnosis is suspected after the pathologic examination of the endoscopic biopsies and definitely documented with the examination of the surgical specimen. CASE PRESENTATION: We are presenting a rare case of a 77-year-old Greek man with epigastric pain of one and a half month duration, nausea, anorexia and weight loss. The pathologic examination of the endoscopic biopsies and a lymph node biopsy excised at laparotomy, presented the interpenetration of synchronous occurring primary gastric lymphoma and a gastric adenocarcinoma with a documented cancer to cancer metastasis. CONCLUSION: Prognosis of these rare tumours is largely dependent on the stage of the adenocarcinoma at presentation but due to lack of large series there are no data on the biological behavior of these tumours in comparison to adenocarcinoma.