A 50-year-old woman presented with dyspepsia but no history of weight loss or gastrointestinal
bleeding. Esophagogastroduodenoscopy (EGD) showed a sessile polypoidal submucosal
lesion in the second part of the duodenum close to the ampulla with a central opening
(fish-mouth appearance) ([Fig. 1]). The contour of this lesion was smooth and there was no disruption of the surrounding
folds, nor ulceration or bleeding. Linear endoscopic ultrasound (EUS) was performed
for evaluation of the lesion. This revealed that the lesion was arising from the mucosa/submucosa
of the duodenum and had a cystic anechoic central core in the submucosa with no solid
component and well-demarcated margins ([Fig. 2]; [Video 1]).
Fig. 1 Esophagogastroduodenoscopy (EGD) showing a sessile polypoidal submucosal lesion in
the second part of the duodenum close to the ampulla with a central opening (fish-mouth
appearance). The contour of this lesion was smooth and there was no disruption of
the surrounding folds, and no ulceration, bleeding, hyperemia, or adjacent mucosal
edema.
Fig. 2 Linear endoscopic ultrasound (EUS) images showing: a a submucosal polypoid lesion with a cystic anechoic core, seen from the duodenum
filled with water; b the polypoidal lesion arising from the mucosa and submucosa of the duodenum; c a cystic anechoic central core in the submucosa without any solid component, along
with well-demarcated margins on zoom imaging, and no blood flow on color Doppler imaging.
Video 1 Esophagogastroduodenoscopy (EGD) showing a sessile polypoidal submucosal lesion in
the second part of the duodenum close to the ampulla with a central opening (fish-mouth
appearance). The lesion is grasped by biopsy forceps and the duodenum is filled with
water for endoscopic ultrasound (EUS) imaging. Linear EUS shows that the heterogeneous
lesion is arising from the mucosa and submucosa of the duodenum and has a cystic anechoic
central core in the submucosa without any solid component. On zoom endoscopy and color
Doppler imaging, the layers of the duodenal wall are well demarcated and the lesion
is avascular. Polypectomy is performed with a snare.
On the basis of the EUS images, it was suspected that this was heterotopic gastric
mucosa (HGM) and therefore the decision was made to resect the lesion endoscopically.
The patient underwent polypectomy and the submucosal lesion was sent for histopathology.
The histopathological examination confirmed the presence of HGM revealing fundal and
pyloric glands covered by duodenal epithelium ([Fig. 3]).
Fig. 3 Histological examination of the polypectomy specimen showing the lesion covered by
normal duodenal mucosa consisting of gastric type foveolar epithelium, gastric fundal
glands, and pyloric glands consistent with heterotopic gastric mucosa.
HGM is common in all organs of the gastrointestinal tract, particularly in the esophagus
and duodenum [1]. A recent study found duodenal HGM appearing as solitary or multiple small nodules
in 1.9 % of 28 210 patients who underwent EGD with duodenal biopsy [2].
EUS for the evaluation of submucosal lesions is a well-established entity, but literature
with regard to the EUS description of duodenal HGM is rare. Hizawa et al. [3] described duodenal HGM presenting as a simple anechoic mass within the submucosa.
In a recent series of six patients with duodenal HGM, the lesions appeared as solitary,
sessile submucosal lesions with a depression at the top [1]. On EUS, these lesions had a heterogeneous pattern with or without an anechoic area
and were located within the mucosa/submucosa.
Although HGM is a benign entity, it may require laparoscopic or endoscopic resection
if the lesion is large in size.
Endoscopy_UCTN_Code_CCL_1AB_2AZ_3AB
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