Cystic Brunner’s Gland Hamartoma in the Gastric Body: A Case Report

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/ by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Cystic Brunner's gland hamartoma has been described under the various names including cystic hamartoma of Brunner's glands, cystic Brunner's gland heterotopia, Brunner's gland cysts, Brun-ner's gland cystadenoma, Brunner's cyst, mucocele of Brunner's glands, and cyst of Brunner's glands. Here, we report a rare case where a patient presented with an incidentally found, and long-standing pedunculated submuco-sal mass in the stomach body, which was diagnosed as a cystic Brunner's gland hamartoma. To the best of our knowledge, no previous occurrence of cystic Brunner's gland hamartoma in the gastric fundic glands has been reported. A previously healthy 72-year-old female presented with a gastric submucosal tumor at the gastric angle. She had been under evaluation for ten years and over this follow-up period, the tumor size increased from 10 mm to 20 mm (Fig. 1A). En-doscopic ultrasound (EUS) showed a heterogeneous mixed hy-poechoic lesion in the third layer of the gastric wall, measuring 20 mm (Fig. 1B). Multiple small compartments were separated by thin-walled septae and a regular border. Because we expected that the patient had a gastric cystic submucosal tumor, including a gastrointestinal stromal tumor with cystic change or a het-erotopic pancreas, endoscopic submucosal dissection was performed using a dual knife and hemostatic forceps. There were no acute complications during the procedure. On gross examination, the resected specimen was polypoid in appearance and had an intact surface. The cut surface showed a multiloculated cyst containing clear fluid (Fig. 2A). On microscopic examination, the polypoid cyst was covered by intact fundic mucosa, and the underlying multilocular cysts consisted of dilated ducts and intermixed fibromuscular bundles in the submucosa (Fig. 2B). The cysts deeply infiltrated mature lym-phoid cells with germinal centers. A few dilated lymphatics and capillaries were observed. The cysts were lined by clear co-lumnar epithelia, similar to that found in Brunner's gland ducts (Fig. 2C). The epithelial lining was observable after staining with periodic-acid Schiff stain, but not with mucicarmine. The overlying fundic mucosa epithelial cells were positive for MU-C5AC (1:500, CLH5, Novocastra Laboratories, Newcastle, UK) and negative for MUC6 (1:500, Ccp58, Novocastra Laboratories). These findings are all consistent with having cystic Brun-ner's gland hamartoma in the stomach. During the ten-month follow-up period, the patient …