the first case was described by cruveilhier in 1835 and termed as hamartoma . till date , less than 200 cases have been described with synonyms of brunner gland adenoma , brunner gland hamartoma ( bgh ) or brunneroma . there is no sex predilection and patients present in the fifth to sixth decades of life . they are usually seen as incidental findings on imaging with duodenal bulb as the most common location . however , it may present with a variety of clinical presentations depending on location and tumor size such as abdominal pain , dyspepsia , nausea , vomiting , upper gastrointestinal ( gi ) bleeding and occasionally obstructive symptoms with associated chronic pancreatitis . a 42-year - old man presented with history of pain epigastrium since one year and recurrent vomiting within half an hour of taking food since one month . a biopsy of duodenum was performed by the same procedure which was diagnosed as well differentiated adenocarcinoma . the patient was further subjected to abdominal computed tomography ( ct ) which showed circumferential thickening of the second part of the duodenum ( 15.2 mm maximum thickness ) abutting head of pancreas with loss of fat planes . laboratory investigations showed normal blood counts , liver , and kidney function tests but elevated serum amylase and lipase levels . this patient underwent radical surgery ( whipple s procedure ) at our institute with clinical diagnosis of carcinoma periampullary region and the specimen was sent for histopathological examination . gross examination of the specimen revealed circumferential thickening of the second part of the duodenum and bulky head of the pancreas . cut section revealed a diffuse grey white area measuring 4x4 cm with few cystic and hemorrhagic areas . six lymph nodes were isolated from the specimen and a single celiac node was examined which was received separately . microscopy showed a tumor composed of lobules of brunner s glands with a dilatation of few glands . these lobules were separated by fine fibrous septa and constituted > 50% of the thickness of the duodenal wall (   figures 1 , 2 and 3 ) . hyperplasia of brunner s glands spanning > 50% of wall thickness ( h&e stain , 4x )   lack of features of anaplasia in proliferating brunner s glands ( h&e stain , 20x ) smooth muscle actin stain highlighting the intervening smooth muscles ( ihc , 10x ) brunner glands are branched acinotubular glands with submucosal location , found exclusively between the pyloric ring and the papillae of vater . their major role is the protection of duodenal epithelium from acidic gastric chyme by secretion of neutralizing alkaline fluid composed of viscous mucin . the pathogenesis of bgh has been linked to excessive local irritation from acidic gastric chyme , vagal stimuli , or unidentified antral hormones . hence , it is associated with conditions related to gastric hyperacidity and changes in gastric emptying such as esophagitis , hiatus hernia , and gastric - peptic ulcer . the association of this tumor with uremia and chronic pancreatitis has also been reported . in a study of patients undergoing pancreaticoduodenectomy , 76% of the patients had diffuse hyperplasia of brunner s gland , raising the question whether this is an adaptation to pancreatic insufficiency . an alternate suggestion for this hyperplasia is that these glands proliferate in reaction to inflammationas evidenced by presence of lymphocytes in the lesion . support to this hypothesis is not rationalized as lymphocytes may be present in normal submucosa of the gastrointestinal tract . in a study on the role of helicobacter pylori infection in the pathogenesis of bgh , 5 of 7 cases with bgh had concurrent helicobacter pylori infection . a definite relationship has not yet been proven because of the high prevalence of helicobacter pylori and rarity of this lesion in the general population . 
 
 initially , the hyperplasia of brunner s gland can be focal , localized , and solitary usually involving a lobule . however , if stimulus persists then the lesion enlarges involving multiple lobules leading to formation of diffuse and annular lesion infiltrating into the wall and circumference of the duodenum . endoscopically these can be nodular , polypoid or diffuse with thickening of the duodenal wall . due to this presentation , these lesions can be misdiagnosed as gastrointestinal stromal tumor ( gist ) , lymphoma , carcinoid , peutz jeghers polyp , prolapsed pyloric mucosa , or aberrant pancreatic tissue . although surface biopsy of this lesion can be misleading as in our case , a deeper biopsy will be more diagnostic . microscopic diagnosis of hyperplasia requires presence of lobules of brunner s glands within the submucosa in at least 50% of the length of the biopsy showing no features of dysplasia . adenoma has been used for lesions > 1 cm and the term  hamartoma if it contains mesenchymal elements also . conflicts regarding this terminology exist as some authors suggest that mere change in size indicate progression of hyperplasia and do not imply neoplastic behavior . ductal malignancy arising from brunner gland adenoma has been reported in one case   which is a very rare circumstance ( 0.5% ) . brunner gland adenoma in the duodenal wall with a focus of atypical cells supported by mib-1 and p53 positivity has also been reported . the treatment of bgh is done with surgical or endoscopic removal in symptomatic patients taking into account the size and gross appearance . although endoscopic techniques of removal are more helpful , this procedure can be limited by difficult anatomical sites . recurrence in such a lesion is not known . 
 
 even though diagnosis of bgh can be made by various imaging studies , in our case hence , these possibilities should be kept in mind while dealing with duodenal masses .
brunner s gland hamartoma is a rare benign tumour of the duodenum . 
 it was first described by cruveilhier in 1835 . 
 presently around 200 cases have been reported in literature . 
 no sex predilection is seen . 
 patients usually present in the fifth to sixth decades of life . they may be clinically silent or may present with variable symptoms and occasionally obstructive symptoms and chronic pancreatitis . 
 endoscopic presentation can be nodular , polypoid or diffuse glandular proliferation with thickening of duodenal wall and hence can be misdiagnosed as malignancy . 
 we describe a case of duodenal tumor reported outside ( on biopsy ) as well differentiated adenocarcinoma which out as brunner gland hamartoma upon complete resection . 
 brunner gland hamartoma may sometimes have a very unusual presentation . 
 extensive pre - operative evaluation is necessity to avoid radical surgical procedure .