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Paper text:
we present a case of gastric outlet obstruction ( goo ) caused by a fibroepithelial tumour .
this is the first instance of such a tumour being identified in the gastrointestinal tract .
interestingly also , our patient experienced no prodromal symptoms relating to gradual occlusion of the gastric outlet , and presented with an acute picture leading to diagnostic confusion initially .
a previously well 57-year - old man presented to our emergency department with a 24hr history of epigastric fullness and discomfort , delayed non - bilious vomiting after oral intake , and anorexia .
the patient took no regular medications and consumed 12 - 14 units of alcohol per week .
initial impressions were of gastritis , biliary colic , or peptic ulcer disease ( pud ) .
blood investigations demonstrated a white cell count of 16.1 x 10 l , c - reactive protein of 247 mg l and normal amylase , liver function , and electrolytes .
endoscopy performed the following day revealed a pre - pyloric submucosal lesion with normal overlying mucosa ( biopsy proven ) , with complete obstruction of the pyloric valve  a diagnosis of goo secondary to a submucosal lesion was made .
a subsequent computed tomography ( ct ) scan demonstrated solid and cystic components within the lesion and no associated significant lymphadenopathy ( figure 1 ) .
these sequential ct image at the level of l1 demonstrates the heterogenous tumour arising from the wall of the distal stomach , and causing total occlusion of the gastric outlet . an endoscopic ultrasound examination ( eus ) , with a view to simultaneous fine needle aspiration cytology ( fna ) was arranged , to further evaluate the lesion .
our patient s symptom continued unabated and despite total parenteral nutrition was failing to thrive .
therefore a laparotomy was performed in which a gastric antral mass was identified ; with the transverse colon adherent to the stomach on the serosal aspect of the mass .
macroscopic examination of the specimen revealed a 9 x 8 cm section of the stomach stapled along two margins , with a 30 cm section of colon , including the caecum and appendix , attached . at the site of adhesion a 7 cm mass was felt . on opening the lumen of both the transverse colon and stomach no lesion or ulceration
was seen ; although there was significant bulging of the gastric mucosa overlying the mass . upon slicing a solid white tumour was seen to arise from the wall of the stomach , approximately 3 cm from the nearest resection margin , with a well defined edge ( figure 2 ) .
here we can see a white , solid tumour , with a well circumscribed edge arising from the wall of the stomach .
microscopic analysis of sections from the stomach revealed a predominantly unremarkable mucosa , with some areas of intestinal metaplasia . just beneath the muscularis mucosa , a nodular
this consisted predominantly of epitheloid , spindle shaped cells set in a collagenous stroma containing thin walled vessels ( figure 3 ) .
this haematoxylin and eosin ( h&e ) stained section demonstrates the epitheloid spindle shaped cells with intervening areas of stromal hyalinisation . in places
the tumour also contained cleft - like spaces lined by gastric and intestinal type epithelium , seen more towards the gastric side of the tumour nodules ( figure 4 ) .
this epithelium was in at least one place continuous , with the normal gastric surface mucosa which was seen to dip down into muscularis mucosa .
in this h&e stained section gastric and intestinal type epithelium is seen lining numerous cleft like spaces within the lesion .
immunohistochemical analysis revealed the stromal component to be strongly smooth muscle actin ( sma ) positive , with patchy , weak positivity forvimentin and caldesmon .
the tumour cells were negative for cluster of differentiation ( cd ) 117 , cd34 , cd99 , cd68 , s100 , activin receptor - like kinase-1 , mnf116 , and human melanoma black -45 .
the epithelial component showed variable positivity , in different areas , for cytokeratin ( ck)-7 and ck-20 .
there was no cytological atypia nor any features of malignancy in either the epithelial or spindle cell elements .
our patient experienced a protracted recovery due to a post - operative pneumonia and episode of haemorrhagic gastritis , but was eventually discharged home and remains well to this date .
considered separately , the epithelial component could not be explained by a developmental cyst or reduplication as an associated smooth muscle component was not seen ; and the stromal elements did not fit with any of the recognised gastrointestinal mesenchymal tumours .
the only logical way to explain the findings in this case was to regard both the stromal and epithelial components as part of the same process , and make a diagnosis of a fibroepithelial lesion of the gastrointestinal tract .
fibroepithelial neoplasias are biphasic lesions , consisting of both a stromal and epithelial components from two separate germ lines  endoderm and mesoderm .
they are most commonly seen in the breast as the phyllodes tumour ( 1 ) .
their behaviour ranges from benign to malignant , and quantitative morphologic criteria  including mitotic rate per 10 high - power fields , stromal cellularity , nuclear size , stromal overgrowth , and the largest and smallest stromal - epithelial surface area ratios - exist to stratify lesions accordingly ( 2 ) . in our case
gastric submucosal lesions are usually evident after endoscopic investigation , which is in turn regularly performed due to the symptom profile of these lesions . in the case of a submucosal gastric lesion , eus with fna of the lesion is the definitive investigation .
this has been shown to be the most reliable in determining whether a lesion is benign or malignant , assessing the suitability of surgical versus endoscopic resection , and can also be used to survey uncertain lesions ( 3 ) .
the addition of fna to eus is reported at achieving an accurate tissue diagnosis of submucosal lesions in 89% of cases ( 4 ) .
definitive management should be planned in accordance with the patient s symptoms and tumour in mind .
resection can be carried out successfully laparoscopically , as shown for gist s ( 5 ) , or by laparotomy in difficult or uncertain cases .
a 57 year old male patient presented to our hospital with vomiting , epigastric discomfort , and loss of appetite over a 24hr period . 
 subsequent investigations demonstrated a submucosal lesion causing gastric outlet obstruction . 
 the patients deteriorating condition mandated laparotomy and a pathologic diagnosis was made of a pyloric submucosal fibroepithelial lesion from the resected distal stomach and adherent transverse colon ; no malignant features were found . 
 this is to our knowledge the first instance of a fibroepithelial neoplasm occurring within the gastrointestinal tract .