[Collision cancer of primary squamous cell carcinoma and adenocarcinoma in the stomach after treatment for a non-Hodgkin's lymphoma of diffuse large B cell type:a case report].

ABSTRACT

We report the case of a 61-year-old woman with a collision cancer of primary squamous cell carcinoma (SCC) and adenocarcinoma in the stomach that was cured surgically. She achieved complete remission after treatment (R-CHOP and radiation therapy;40.8Gy/22Fr) for a non-Hodgkin's lymphoma of diffuse large B cell type from September 2016 to April 2017. In August 2018, endoscopic findings showed a type 3 tumor with a white coat on the posterior wall of the upper gastric body. A biopsied specimen showed that the tumor was a SCC. Total gastrectomy, distal pancreatectomy, splenectomy, and D2 lymph node dissection were performed. Pathological examination showed a SCC invasion to the spleen, and normal gastric mucosa between the esophagus and SCC of the stomach. Based on the pathological TNM classification, the tumors were T4N1M0 (Stage IIIB) for the SCC and T1N0M0 (Stage IA) for the adenocarcinoma of the stomach. The patient received adjuvant chemotherapy with S-1, and was recurrence free at 9 months after the surgery.