An unusual presentation of Helicobacter pylori infection: so-called "Russell body gastritis".

Helicobacter pylori (H. pylori) is a "slow" bacterial pathogen, which induces several gastroduodenal diseases. Varying degrees of inflammation can be present in the gastric mucosa of patients infected with H. pylori. The case presented here is a male patient suffering from dyspepsia and nausea. His upper gastrointestinal endoscopy revealed pan gastritis. Histological examination of multiple gastric biopsies taken from the body and antrum showed a rare morphological expression of H. pylori gastritis characterized by diffuse plasma cell infiltration with extensive Russell body formation. Diffuse infiltration of plasma cells with Russell bodies in gastric mucosa can cause difficulties in differentiation from neoplastic processes. However, immunohistochemically, the infiltrating cells in the gastric mucosa stained negatively with cytokeratins while they expressed both kappa and lambda light chains showing their polyclonal nature. The presence of diffuse plasma cells with Russell bodies in the gastric mucosa may represent a different presentation of H. pylori gastritis. There are only two case reports of similar presentation and both have been called "Russell body gastritis".