Published online Aug 16, 2017. doi: 10.4253/wjge.v9.i8.417
Peer-review started: December 1, 2016
First decision: February 20, 2017
Revised: March 13, 2017
Accepted: April 23, 2017
Article in press: April 24, 2017
Published online: August 16, 2017
Processing time: 254 Days and 14 Hours
Russell body gastritis (RBG) is an unusual type of chronic gastritis characterized by marked infiltration of Mott cells, which are plasma cells filled with spherical eosinophilic bodies referred to as Russell bodies. It was initially thought that Helicobacter pylori (H. pylori) infection was a major cause of RBG and that the infiltrating Mott cells were polyphenotypic; however, a number of cases of RBG without H. pylori infection or with monoclonal Mott cells have been reported. Thus, diagnostic difficulty exists in distinguishing RBG with monoclonal Mott cells from malignant lymphoma. Here, we report an unusual case of an 86-year-old-Japanese man with H. pylori-positive RBG. During the examination of melena, endoscopic evaluation confirmed a 13-mm whitish, flat lesion in the gastric antrum. Magnification endoscopy with narrow-band imaging suggested that the lesion was most likely a poorly differentiated adenocarcinoma. Biopsy findings were consistent with chronic gastritis with many Mott cells with intranuclear inclusions referred to as Dutcher bodies. Endoscopic submucosal dissection confirmed the diagnosis of RBG with kappa-restricted monoclonal Mott cells. Malignant lymphoma was unlikely given the paucity of cytological atypia and Ki-67 immunoreactivity of monoclonal Mott cells. This is the first reported case of RBG with endoscopic diagnosis of malignant tumor and the presence of Dutcher bodies.
Core tip: We report Russell body gastritis (RBG) evaluated by magnification endoscopy with narrow band imaging and pathological evaluation by endoscopic submucosal dissection. The endoscopic features of RBG are exclusively inflammatory; however, our detailed endoscopic evaluation led to misdiagnosis of the lesion as poorly differentiated adenocarcinoma. The histological features of RBG were also unique because the presence of Mott cells with light chain restriction and Dutcher bodies suggested malignant lymphoma. Pathologists should be aware of the existence of this pathological entity, and clinicians should consider RBG as a differential diagnosis in cases where detailed endoscopic examination reveals poorly differentiated early gastric cancer.