Gastric Adenomyoma with Heterotopic Pancreatic Tissue.

Sir,

We read with a keen interest the recent article published in JIAPS by Anand et al.,[1] in which they reported a case of gastric adenomyoma in a 12-year-old child who presented with gastric outlet obstruction (GOO). Although gastric adenomyoma is an extremely rare case of GOO in children, we would like to report another similar case of this rare disease which we managed recently at our center.

A 6-year-old boy presented to us with a history of vomiting for the past 9 months. The vomitus was nonbilious and contained previously ingested food particles. The frequency of vomiting had increased significantly in recent times and the boy was now vomiting 15–20 min after every meal. Intake of food was associated with borborygmi and visible peristalsis. The boy had lost significant weight in the past 6 months and the weight was below 10th centile for age. Abdominal examination revealed fullness in the epigastric region with visible peristalsis. However, there was no lump or organomegaly.

Laboratory parameters were normal except for mild anemia and hypoalbuminemia. Ultrasonography of the abdomen showed a hypoechoic lesion in the gastric antropyloric wall with diffuse thickening of antropyloric canal and proximal duodenum. Upper gastrointestinal (UGI) contrast study revealed pyloroduodenal and adjacent gastric wall thickening, causing luminal narrowing and irregularity with deformed duodenal bulb and C-loop [Figure 1a]. Computerized tomography enterography revealed a heterogeneously enhancing submucosal lesion (1.9 cm × 1.1 cm) in the anterior wall of the antropyloric region, causing luminal obstruction leading to proximal dilatation of the stomach [Figure 1b]. UGI endoscopy was done which showed a bulge in the antrum just above the pylorus with thickened folds and erythema [Figure 2a]. Endoscopic mucosal biopsies were taken which on histopathological examination were inconclusive.

Figure 1

(a) Upper gastrointestinal contrast study showing pyloroduodenal thickening causing luminal narrowing (arrow) and irregularity with deformed duodenal bulb and C-loop and (b) computerized tomography enterography showing a heterogeneously enhancing lesion in antropyloric region (arrow) causing luminal obstruction

Figure 2

(a) Upper gastrointestinal endoscopic image showing a bulge in the antrum just above the pylorus with thickened folds and erythema and (b) intraoperative photograph showing a mass (arrow) circumferentially involving the antrum and pylorus with extension till the 1st part of the duodenum

The patient posed a diagnostic dilemma and the differential diagnosis included stromal tumor, lymphoma, or tuberculosis. An exploratory laparotomy revealed a hard mass involving almost 75% circumference (antero-superior-inferior surface) of the antrum and pylorus with extension till the 1st part of the duodenum, and the proximal stomach was thick walled and distended [Figure 2b]. Antrectomy with Roux-en-Y gastrojejunostomy was performed. Postoperative period was uneventful. The boy was discharged on full oral feeds and is asymptomatic at 1-year follow-up.

Histopathology of the specimen revealed an antropyloric tumor measuring 2.6 cm × 2.1 cm and involving the whole thickness of the gastric wall from muscularis to serosa. Microscopic sections showed gastric mucosa displaying multiple ectopic dilated ducts with Brunner's glands within disordered broad muscle bundles and submucosal aberrant pancreatic tissue. Panmural inflammatory granulation tissue, especially around the aberrant glands, comprising dense mixed inflammatory cell infiltrate with multinucleate giant cells, proliferating blood vessels, along with periodic acid-Schiff-positive foreign body material, was also seen. All resection margins were free of tumor. The final diagnosis was gastric adenomyoma with heterotopic pancreatic tissue.

We would like to commend Anand et al. for managing and reporting this very rare entity with extensive review of literature.[1] They have mentioned that only 52 cases of gastric adenomyoma have been reported in the literature till 2017. However, we would like to point out that most of these cases are in adults and the cases reported in children till date will not even reach double digits.[2] Another interesting finding in our case is the presence of heterotopic pancreatic tissue on histopathological examination. As reported previously, the etiopathogenesis of gastric adenomyoma is debatable between it being a developmental aberration versus an abortive variant of heterotopic pancreas.[3] The presence of heterotopic pancreatic tissue in our case certainly supports the latter.

To conclude, gastric adenomyoma is an extremely rare cause of GOO in children. The reporting of two cases in children in quick succession as seen here is even rarer. It usually remains undiagnosed till surgical excision and detailed histopathological examination is done. The outcome is usually favorable as malignant transformation and recurrence is very rare.

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The authors certify that they have obtained all appropriate patient consent forms. In the form, the patients have given their consent for their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.