mesenteric pseudocyst is a term used to describe abdominal cystic mass without the origin of abdominal organ.(1 ) this has been classified according to embryologic , ehiologic , histologic , and ther data , causing considerable confusion .
it was considered the term mesenteric cyst as merely descriptive , and apply a histologic classification such as lymphangioma , pseudocyst , enteric duplication cyst , enteric cyst , and mesothelial cyst.(2 ) we presented a case of mesenteric pseudocyst of the small bowel in a 70-year - old man .
a 70-year - old man was referred to our hospital for operation of gastric cancer with a 1-month history of progressively worsening epigastric and intermittent peri - umbilical discomfort .
he had no specific previous medical or surgical history including cancer . on physical examination ,
esophago - gastro - duodenoscopy ( egd ) showed a 3.5 cm sized excavated lesion on the posterior wall of angle .
endocopic biopsy confirmed a histologic diagnosis of poorly differentiated adenocarcinoma including signet ring cell component .
endoscopic ultrasonography revealed invasion of caner to the proper muscle layer . abdominal computed tomography ( ct )
scan showed a focal mucosal enhancement in posterior wall of angle of stomach , a 2.4 cm sized enhancing mass on distal small bowel loop without distant metastases or ascites in rectovesical pouch , and multiple gallbladder stones ( fig .
1 ) . these physical , laboratory , and radiological findings prompted us to diagnose early gastric cancer , and gastrointestinal stromal tumor of small bowel .
laboratory testing revealed alfa - fetoprotein level of 2.88 ( normal range , 0 to 9 ng / ml ) , carcino - embryonic antigen level of 1.45 ng / ml ( normal range , 0 to 5 ng / ml ) , carbohydrate antigen ( ca ) 19 - 9 level of 6.5 u / ml ( normal range , 1 to 35 u / ml ) , and ca 72 - 4 level of 4.8 u / ml ( normal range , 0 to 4 u / ml ) . other laboratory test results were within normal limit .
the patient underwent subtotal gastrectomy with gastroduodenostomy , segmental resection of small bowel , and cholecystectomy .
mesenteric mass was adhered severely with greater omentum at the mesenteric side of small bowel , and mesenteric fat tissues .
small bowel , mesentery , and mesenteric mass were resected en - bloc methods , and end to end anastomosis was performed .
after fixation of the surgical specimen , macroscopic examination revealed a uni - locular cyst measuring 332 cm in size .
pathological examination revealed 3 cm sized fibrous cystic wall without endothelial or epithelial lining and foam cell collection ( fig . 2 , 3 ) .
pathologic stage of gastric cancer was t1bn1m0 ( 6th international union against cancer tnm staging system ) ; invasion to submusosa , metastases to 4 perigastric lymph nodes out of 16 retrieved nodes , and negative resection margin .
mesenteric pseudocysts are very rare intraabdominal mass with an incidence of about 1 case per 100,000 hospital admissions.(3 ) ros et al.(2 ) first used the term " pseudocyst " in the classification of mesenteric cyst .
mesenteric pseudocyst could be located in the small bowel , large bowel mesentery and even retroperitoneum.(1,4 ) most reports were pseudocyst of large bowel or retroperitoneum.(1 ) although most mesenteric pseudocysts are asymptomatic , symptomatic mesenteric cysts could be associated with cyst size , cyst location , and complications , including infection , rupture , hemorrhage , and intestinal obstruction.(5 ) in our patient , there was no specific symptom associated with mesenteric pseudocyst except for intermittent vague periumbilical discomfort . if egd and ct scan were not performed in this patient presenting non - specific abdominal pain , the diagnosis of mesenteric pseudocyst would be delayed . to the best of our knowledge ,
this is the first case report describing incidentally detected mesenteric pseudocyst of small bowel in gastric cancer patients .
when clinician performed staging work up for gastric cancer , should be aware the possibility of associated intraabdominal lesions .
 mesenteric pseudocyst is rare . 
 this term is used to describe the abdominal cystic mass , without the origin of abdominal organ . 
 we presented a case of mesenteric pseudocyst of the small bowel in a 70-year - old man . 
 esophago - gastro - duodenoscopy showed a 3.5 cm sized excavated lesion on the posterior wall of angle . 
 endocopic biopsy confirmed a histologic diagnosis of the poorly differentiated adenocarcinoma , which includes the signet ring cell component . 
 abdominal computed tomography scan showed a focal mucosal enhancement in the posterior wall of angle of the stomach , a 2.4 cm sized enhancing mass on the distal small bowel loop , without distant metastases or ascites in rectal shelf , and multiple gallbladder stones . 
 the patient underwent subtotal gastrectomy with gastroduodenostomy , segmental resection of the small bowel , and cholecystectomy . 
 the final pathological diagnosis was mesenteric pseudocyst . 
 this is the first case report describing incidentally detected mesenteric pseudocyst of the small bowel in gastric cancer patients . 
Introduction
Case Report
Discussion