A Case of Adenocarcinoma of the Duodenum Arising from Brunner's Gland
A 70-year-old man was referred to our hospital for investigation of his abdominal discomfort. He had been followed with a diagnosis of diabetes mellitus for 45 years. On admission, physical examination showed no abnormalities, and all laboratory data were normal, except for an elevation in CEA and CA19-9. His CEA level was 128 ng/ml (normal 0–5 ng/ml) and his CA19-9 was 326 U/ml (normal 0–37 U/ml). Upper gastrointestinal endoscopy revealed an irregular elevated mucosa (fig. ) and a submucosal tumor with delle in the duodenal bulb (fig. ). Biopsy specimens revealed adenocarcinoma (the former) and hyperplasia (the latter). Abdominal computed tomography confirmed the presence of a mass originating in the submucosal layer of the duodenal bulb.\nUnder the diagnosis of adenocarcinoma of the duodenum, we proposed to perform pancreaticoduodenectomy, but the patient did not consent. Thus, partial resection of the bulbus and the antrum was performed instead. At laparotomy, we saw that the tumor had not invaded the serosa and that lymph node swelling was limited, so we dissected the lymph nodes, including No. 6, 8a, 8p, 12a and 16b1. The resected specimen showed two tumor types, in accordance with the preoperative findings (fig. ). Pathological examination of the oral side of the tumor showed that it was consistent with normal Brunner's glands (fig. , black arrows), Brunner's gland hyperplasia (fig. , white arrow) and adenocarcinoma supposed to arise from Brunner's glands (fig. , black arrowheads). The anal side of the tumor also revealed Brunner's gland hyperplasia and adenoma supposed to arise from Brunner's glands (fig. ). Immunohistochemical staining revealed that the site of normal and hyperplasia gland was positive for MUC5AC (data not shown) and MUC6 (fig. ), but the site of adenoma and adenocarcinoma was negative. Lymph node metastasis was positive for No. 6 and 8a. The patient's postoperative course was good, but adjuvant chemotherapy was not done because the he refused it. Fifteen months after the operation, laboratory data showed high levels of CEA and CA19-9 (45 ng/ml and 237 U/ml). Positron emission tomography and computed tomography revealed a tumor located near the head of the pancreas. Under the diagnosis of lymph node metastasis of duodenal cancer, we did pancreaticoduodenectomy. Pathological examination confirmed our preoperative diagnosis. The patient received adjuvant chemotherapy with S-1 and remained well after the surgery for 2 years.