Endoscopic and pathologic motifs for the clinical diagnosis of Epstein-Barr virus-associated gastric cancer.

Objectives: Based on the recent therapeutic trends for gastric cancer (GC), the clinical impact of the diagnosis of Epstein-Barr virus (EBV)-associated GC (EBVaGC) appears to be important. We retrospectively analyzed endoscopic and pathologic motifs of GC lesions to narrow the number of candidates for EBV testing. Methods: We performed EBV tests for 32 upper gastrointestinal lesions of 32 patients in the clinical setting. These tests were ordered by endoscopists or by pathologists without an endoscopist's order. EBV-encoded small RNA1 (EBER1) in situ hybridization was used for the EBV tests. The endoscopic motif for the EBV test was the location in the upper part of the stomach or remnant stomach, mainly the depressed type with a submucosal tumor-like protrusion of the lesion. The pathologic motif was carcinoma with lymphoid stroma (CLS) or CLS-like histology of the lesion. We retrospectively analyzed the results of EBV tests for the endoscopic and pathologic motifs. Results: The final pathological diagnoses of the 32 subjects were 26 GCs including CLS, gastric endocrine cell carcinoma, gastric hepatoid carcinoma, gastric T-cell lymphoma, gastritis of the remnant stomach, esophageal adenocarcinoma, and esophageal squamous cell carcinoma. When nontypical lesions were excluded, the EBER1-positive rate was 42.3% (11/26) in GCs. Of the 14 GC lesions ordered examined by endoscopists, three (21.4%) were EBVaGC. Eight of the 12 (66.7%) GCs ordered examined by pathologists were EBVaGC. Conclusions: The pathologic motif is expected to be useful and the endoscopic motif may be helpful for EBVaGC diagnosis.