A Case of Collison Tumor with Squamous Cell Carcinoma and Malignant Lymphoma in the Cardia

Abstract

A 73-year-old woman visited the Oita Medical University Hospital with a complaint of dysphagia. Esophagectomy and total gastrectomy were performed. The patient was alive 51 months after the operation without any sign of recurrence. Pathological examination of the resected specimen showed a Borrmann type-2 lesion measuring 5.0×5.0cm and a IIc lesion measuring 10.9×9.0cm located close to each other in the cardia of the stomach. Microscopic examination revealed a collison tumor consisting of poorly differentiated squamous cell carcinoma and malignant lymphoma. The serial sections showed that there was no histological transition between the two components. With respect to metastatic sites in the lymph nodes, only one component from each tumor was seen. The constituent cells of the squamous cell carcinoma demonstrated positive immunoreactivity for keratin and EMA. Lymphoma cells showed positive immunoreactivity for LCA. Thus, the histological findings of the two tumors confirmed a collison tumor.