Gastric collision tumor of adenocarcinoma and MALT lymphoma: A rare case report and literature review

• Published in: International journal of surgery case reports 2024-12, Vol.125, p.110556, Article 110556
• Main Authors: Omry, Ahmed, Ferjaoui, Wael, Megdiche, Sadok, Omrani, Sahir, Slama, Sana Ben, Bacha, Dhouha
• Format: Article
• Language: English
• Subjects: Adenocarcinoma; Case Report; FLOT chemotherapy; Gastric collision tumor; Lymphoma; Total gastrectomy
• ISSN: 2210-2612; 2210-2612
• DOI: 10.1016/j.ijscr.2024.110556

Gastric collision tumors, characterized by the coexistence of two distinct malignancies within the same organ, are exceptionally rare. We report a case involving a gastric collision tumor composed of adenocarcinoma (ADK) and marginal zone lymphoma, diagnosed postoperatively. To date, only six cases of MALT lymphoma as part of gastric collision tumors have been published, highlighting the rarity of this association. A 58-year-old male with type 2 diabetes and a family history of breast cancer presented with six months of anemia and epigastric pain. Endoscopy showed a 5 cm ulcerated, friable gastric mass, and biopsies indicated a low-grade tubular adenocarcinoma. Imaging revealed gastric wall thickening and lymphadenopathy. He received FLOT chemotherapy followed by total gastrectomy with Roux-en-Y reconstruction. Histopathology confirmed a gastric collision tumor with a minimal adenocarcinoma remnant and extensive MALT lymphoma. Collision tumors are rare and present unique diagnostic and therapeutic challenges due to the coexistence of distinct malignancies. This case highlights the complexity of managing such tumors, as accurate diagnosis requires comprehensive histopathological analysis. The dual presence of adenocarcinoma and MALT lymphoma necessitated a tailored approach with FLOT chemotherapy and total gastrectomy. The patient's ongoing adjuvant chemotherapy emphasizes the need for vigilant, long-term follow-up to monitor for recurrence and potential metachronous malignancies. Gastric collision tumors involving ADK and MALT lymphoma are rare and challenging. This case contributes to the limited literature on collision tumors, highlighting the necessity for comprehensive diagnostic and therapeutic strategies. •This case report documents a rare gastric collision tumor, featuring both adenocarcinoma (ADK) and MALT lymphoma.•Gastric collision tumors are extremely uncommon, with limited case reports detailing the coexistence of these two malignancies.•The case emphasizes the importance of a multidisciplinary approach in diagnosis, treatment planning, and follow-up for such complex neoplasms.•Detailed histopathological analysis was crucial in confirming the diagnosis and guiding the personalized treatment strategy for gastric collision tumors.•The report adds valuable insights into the clinical management and prognosis of gastric collision tumors, contributing to the scarce literature on these rare cases.