russell body duodenitis ( rbd ) is a rare inflammatory disease characterized by an abundance of polyclonal plasma cells present in the duodenal mucosa . these plasma cells contain intracytoplasmic eosinophilic globules of condensed immunoglobulin , the so - called russell body . we describe the case of a patient with rbd in whom endoscopic and histopathologic findings were observed chronologically , along with a review of the relevant literature . he was found to have a nodule in the right middle lung field on a plain chest radiograph at a local clinic , and was referred to our hospital for detailed examination . a nodule measuring 2 cm was detected in segment 8 of the right lung on chest plain computed tomography ( ct ) . the morphology of the nodule was lobulated , and cavitation was observed in the interior . results of smear , culture , and polymerase chain reaction assay from sputum specimens were all negative for tuberculosis . bronchoscopy was performed on hospital day 9 , during which bronchial lavage fluid was collected , and a biopsy of the nodule was performed . double capsule - like circular objects were positive for periodic acid - schiff stain and grocott stain , yielding a diagnosis of pulmonary cryptococcosis . moreover , the level of the cluster of differentiation ( cd ) 4 was 570/l , the cd8 level was 655/l , and the cd4/cd8 ratio was 0.87 , suggesting no evidence of aids . on hospital esophagogastroduodenoscopy ( egd ; day 14 ) revealed a significant amount of residue and an irregular ulceration with surrounding elevation of the duodenal bulb ( fig . 1a ) , which had brought about severe stenosis . with the suspicion of duodenal cancer , biopsy samples were obtained from ulcer edges . although admixed with various inflammatory cells , necrotic tissues were observed , but no definition of adenocarcinoma cells was found ( fig . however , since some large atypical cells were admixed with infiltrating inflammatory cells , reexamination was required to rule out undifferentiated carcinoma and malignant lymphoma . the second egd ( day 21 ) and the third egd ( day 30 ) revealed no signs of ulcer healing . contrast - enhanced upper gastrointestinal radiography ( day 37 ) revealed severe stenosis from the duodenal bulb to the superior duodenal angle ( fig . 2 ) . positron emission tomography - ct was performed to screen the whole body for malignant tumors . no significant accumulation of fluorodeoxyglucose was observed in any site except the lesion of pulmonary cryptococcosis in the right lung , and no accumulation was detected in the duodenal bulb . considering this benign stenosis , we performed a gastrojejunostomy ( day 43 ) , and thereafter , oral intake became possible . the fourth egd ( day 56 ) revealed that the peripheral redness and edema of the ulcers had become more severe than in the previous findings ( fig . biopsy samples revealed dissemination of large cells with eosinophilic cytoplasms and eccentric nuclei in the necrotic / granulation tissue of the duodenal lamina propria ( fig . 3b ) . the large cells were cd20( ) , cd68( ) , cd79a(+ ) , and s100( ) , and they were  chain(+ ) or  chain(+ ) , suggesting russell bodies derived from polyclonal plasma cells ( fig . the fifth egd ( day 91 ) revealed that the ulcers in the duodenal bulb had reduced in size , and some scarring was present ( fig . although a biopsy at this time confirmed the presence of a few russell bodies , the majority had disappeared ( fig . the patient is being followed up while continuing the oral administration of a proton pump inhibitor ( ppi ) . hsu et al .   showed that russell bodies originate from distended rough endoplasmic reticulum in which immunoglobulin is inhibited from being secreted and condensed . tazawa and tsutsumi   first reported russell body gastritis ( rbg ) in 1998 , in which russell bodies were found in many plasma cells infiltrating the gastric mucosa . first reported in a patient positive for hiv ; only five cases have since been reported [ 5 - 8 ] . the differential diagnoses include plasmacytoma , mucosa - associated lymphoid tissue lymphoma , and signet ring cell carcinoma . in the present case , because the russell bodies were derived from plasma cells positive for cd79a and were suggested to be polyclonal by the mixture of  and  chain - positive cells , rbd was diagnosed . many patients with rbg are positive for h. pylori , which is believed to be associated with the development of rbg . however , only one of the five previously reported cases of rbd was positive for h. pylori . the other background diseases were hiv infection in one , crohn disease in one , retroperitoneal metastasis of ureteral cancer in one , and adenocarcinoma of the ascending colon in one case . although the development of russell bodies is assumed to be associated with chronic inflammation , microorganisms , and immunodeficiency , the causes of their development remain unknown . although russell bodies are frequently found in benign tissue adjacent to a malignant tumor , there are also reports suggesting that the production of chemokines in tumor cells is associated with the development of russell bodies . in the present case , the patient was negative for h. pylori and hiv , and there was no evidence of malignancy or immunodeficiency . we could chronologically observe the endoscopic appearance and histopathological findings of rbd in our patient . when the ulcers were first detected , although severe infiltration of inflammatory cells was observed , rbd was not manifested . through the aggravation of the ulcers furthermore , the fifth egd revealed a tendency for the ulcers to heal , and the majority of the russell bodies had disappeared . from these processes , it was assumed that the russell bodies were not a cause of the ulcerations , but byproducts secondarily induced by a severe inflammatory state after the development of the ulcers . in the present case , because food residues were always retained in the duodenal bulb , mechanical stimulation might also have been associated with the development of the russell bodies . regarding therapeutic responses of russell bodies , there is a report of patients with rbg who were positive for h. pylori , in whom the endoscopic findings improved after h. pylori eradication and the russell bodies disappeared . the present patient was negative for h. pylori and had not undergone h. pylori eradication . his treatment consisted of administration of a ppi and gastrojejunostomy , which are assumed to have contributed to the resolution of the local inflammation . as for the correlation with the degrees of inflammation at the ulcer site , the russell bodies would be expected to appear and disappear as the degree of inflammation changed . the prognosis was favorable with the internal use of a ppi in cases of rbg negative for h. pylori . there have been no published reports of recurrence or malignant transformation during follow - up . however , it is often difficult to distinguish russell bodies from plasmacytoma , mucosa - associated lymphoid tissue lymphoma , and signet ring cell carcinoma . multiple endoscopic observations and biopsies , like that used in the present case , are required to diagnose malignant disease . this was a valuable case in which the clinical and pathological features of rbd , an extremely rare disease , could be compared in the present patient from onset to healing .
a 64-year - old man was found to have a nodule in his right lung . 
 he also complained of nausea and abdominal pain during the clinical course . 
 esophagogastroduodenoscopy revealed a duodenal ulcer associated with severe stenosis and a suspicion of malignancy . 
 however , three subsequent biopsies revealed no evidence of malignancy . 
 the fourth biopsy showed scattered large eosinophilic cells with an eccentric nucleus , leading to a diagnosis of russell body duodenitis ( rbd ) . 
 rbd is an extremely rare disease , and little is known about its etiology and clinical course . 
 the pathogenesis of rbd is discussed based on our experience with this case .