Gastric carcinoma with lymphoid stroma diagnosed by endoscopic ultrasound-guided fine-needle aspiration.

A 78-year-old man with a subepithelial lesion (SEL) in the gastric body and two carcinomas in the gastric antrum was referred to our hospital. Following a diagnosis of SEL, the patient was followed-up by esophagogastroduodenoscopy annually for 4 years. Although the SEL had increased in size over the years, histological evaluation of the forceps biopsies did not reveal any significant findings. We detected a hypoechoic mass in the submucosa by endoscopic ultrasonography, and suspected the lesion to be an aberrant pancreas or mesenchymal tumor. The patient first underwent endoscopic submucosal dissection for the 2 gastric cancers. Histological examination of the resected specimens revealed intramucosal well-differentiated tubular adenocarcinomas. Next, endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) was performed for the gastric SEL. Aspirated specimens revealed an adenocarcinoma with lymphocyte infiltration. The lesion was diagnosed as a gastric carcinoma with lymphoid stroma (GCLS). Subsequently, he underwent distal gastrectomy, and the surgical specimen was confirmed as GCLS corresponding to preoperative diagnosis. In addition, the adenocarcinoma cells were positive for Epstein-Barr (EB) virus-encoded small RNA-1 by in situ hybridization. Finally, the lesion was diagnosed as GCLS associated with EB virus. Thus, EUS-FNA is advantageous for diagnosing GCLS associated with EB virus.