in the hepatobiliary system adenomyoma is rare outside the fundus of gallbladder but can arise throughout the entire biliary tree including papilla of vater.(1 ) according to who classification , adenomyoma and adenomyomatous hyperplasia are defined as duct like structures accompanied by hyperplasia of smooth muscle cells.(2 ) despite its benign nature , presentation of ampullary adenomyoma as biliary obstruction leads to clinical misdiagnosis as carcinoma and is usually treated by extensive surgery .
we present 3 cases of adenomyoma of ampulla presenting as obstructive jaundice for which pancreaticoduodenectomy was performed .
all pancreatico - duodenectomy cases received in the department of pathology for 3 consecutive years at our institute were reviewed and we found 3 cases of adenomyoma .
all three patients were males with ages of 58 years , 65 years and 81 years and presented with abdominal pain , obstructive jaundice and loss of appetite .
ultrasonography showed dilatation of common bile duct in all 3 cases but no obvious mass in two ( 58y male , 65y male ) and a nodule at ampulla measuring 1.51 cm in third case ( 81y male ) .
macroscopically the ampulla was firm and showed a well defined lesion measuring 0.8 cm and 1.5 cm respectively in our first and third case ( 58y male , 81y male ) .
the second case ( 65y male ) had firmness at ampulla but did not show any lesion .
the lesion was composed of proliferating benign glands of varying size lined by gastric antral epithelium and separated by bands of fibromuscular tissue .
adenomyoma is a rare benign lesion arising anywhere in the gut with sign and symptoms depending on size and location .
patients with ampullary adenomyoma usually present with features of biliary obstruction and weight loss with rare reports of acute pancreatitis.(3 ) diagnosis is confirmed by histological examination which is not always possible on endoscopic biopsies particularly if lesions are not visible at the ampulla .
ercp image can be a useful diagnostic approach as it allows inspection of periampullary region and visualization of bile duct and pancreatic duct .
people have used endoscopic snare removal in polypoidal lesions however this may sometimes cause pancreatitis as a complication.(4 ) histollogically the epithelial component can show pancreatic , gastric , intestinal or brunner gland tissue , which can be confused with ectopic pancreatic tissue , myoepithelial hamartoma , fibroadenoma , and mesenchymal lesions .
if the differentiation is into various abnormally arranged pancreatic and glandular elements , terms like adenomyoma , myoepithelial hamartoma , adenomyosis and foregut choristoma are used.(5 ) awareness of adenomyoma is important as it is a rare lesion mimicking carcinoma clinically as well as radiologically .
pathologist should be familiar with morphological features so that it is not mistaken for well differentiated adenocarcinoma because of smooth muscle fibers running in between glands .
 adenomyoma is a rare benign lesion occurring commonly in the fundus of the gallbladder in the biliary tract . 
 ampullary adenomyoma is rarer still , presenting as obstructive jaundice due to its location at the ampulla and may mimic malignancy on clinical and radiological examination . 
 endoscopic biopsy may not be always diagnostic if the lesion is deep seated . 
 histologically these lesions show a combination of diverse benign epithelial and mesenchymal elements , which should not be confused with an invasive tumor because of its arrangement . 
 we report three cases of adenomyoma located at the ampulla presenting as obstructive jaundice . 
 the diagnosis was confirmed on pacreaticoduodenectomy resection specimens . 
INTRODUCTION
CASE REPORT
DISCUSSION