A 70-year-old man was admitted to our hospital because of a duodenal submucosal tumor (SMT) that had been detected during screening gastrointestinal endoscopy. The SMT, which was 10 mm in diameter with a small orifice at the top of the lesion, was located in the first part of the duodenum. Histopathology of a biopsy from the orifice gave a diagnosis of adenocarcinoma. Therefore, endoscopic submucosal dissection (ESD) was performed to remove the lesion en bloc (Fig. 1). Pathological examination (hematoxylin and eosin staining) of the resected specimen revealed a moderately differentiated tubular adenocarcinoma that had invaded the submucosa, but not the lymphatic vessels or vessels; tumor margins were negative (Fig. 2A,B). Immunohistochemical staining revealed that the carcinoma cells were positive for MUC6 (Fig. 2C), but negative for pepsinogen 1 (Fig. 2D). Thus, this duodenal tumor was confirmed as a duodenal carcinoma arising from Brunner’s gland.
Figure 1 (A) Gastrointestinal endoscopy revealed submucosal tumor with a small orifice in the first part of the duodenum; (B) ulcer after endoscopic submucosal dissection; and (C) specimen
Figure 2 Pathological examination (hematoxylin and eosin staining: (A) ×40, (B) ×400) of the resected specimen revealed a moderately differentiated tubular adenocarcinoma that had invaded the submucosa. (C) Immunohistochemical staining revealed that the carcinoma cells were positive for MUC6, but (D) negative for pepsinogen 1
Duodenal adenocarcinoma from Brunner’s gland is very rare and most cases are treated by surgical resection [1]. Brunner’s gland is a mucus-secreting acinar gland located in the submucosa of the duodenum. Therefore, an adenocarcinoma arising from Brunner’s gland resembles an SMT. ESD can be a good treatment selection in adenocarcinoma of duodenum from Brunner’s gland.