Duodenal mucosa-associated lymphoid tissue lymphoma masquerading as an ulcer scar.

clinic because of gastric malignancy found on a periodic medical check−up. He had no specific symptoms or signs. Physical examination and routine labora− tory studies were normal. Esophagogas− troduodenoscopy revealed early gastric cancer (EGC) in the antrum, and there was an additional reddish ulcer scar with fold convergence in the anterior wall of the duodenal bulb. Unlike typical ulcer scar tissue, its mucosa showed patchy erythema and friability. Blood oozed after light touch by the scope (l" Fig. 1). Thus, a biopsy specimen was also taken from the duodenal bulb. Interestingly, histology showed infiltration of atypical lympho− cytes with lymphoepithelial lesions. En− doscopic ultrasound (GF−UM 2000, Olympus, Tokyo, Japan) demonstrated hypoechoic wall thickening of the second sonographic layer and focal interruption of the third layer of the duodenum (l" Fig. 2). There were no abnormalities in bone marrow biopsy, abdomen and chest computed tomography scan. He un− derwent subtotal gastrectomy 4 weeks later. Histological examination revealed that atypical lymphocytes infiltrated dif− fusely into the mucosal and submucosal layer of the duodenal bulb (l" Fig. 3). Mucosa−associated lymphoid tissue (MALT) lymphoma rarely affects the duo− denum. To date, there have been 19 cases of primary duodenal MALT lymphoma in the English literature. Endoscopic fea− tures of duodenal MALT lymphoma in− clude irregular bumpy mucosa, ulcera− tion, and polypoid appearance. Of the 19 cases, six had ulceration (active ulcers) [1 ±4]. The life cycle of the malignant ul− cer is well known in EGC [5]. Therefore, it could appear to be healed. We think that even duodenal MALT lymphoma that forms an ulcer crater may be healed to re− semble an ulcer scar like this. Contrary to gastric ulcer, most duodenal ulcers do not need biopsy. In this case, if a biopsy had not been taken from the duodenum, it would have been regarded as a simple ul− cer scar. Therefore, endoscopic biopsies are mandatory even for duodenal ulcer scars, if they seem to be slightly atypical. Endoscopy_UCTN_Code_CCL_1AB_2AZ_3AB