Heterotopic gastric mucosa and intestinal atresia in a neonate

Abstract

Jejunal atresia is a well-known congenital malformation attributed to in utero ischemic events. Heterotopic gastric mucosa (HGM), or gastric tissue present in a location other than the stomach, is a much rarer congenital anomaly and is generally found in the esophagus or within a Meckel’s diverticulum. Identifying both within the same pathologic specimen is truly rare. This report outlines a case of jejunal atresia wherein HGM was identified within postoperative pathology evaluation of the specimen. An early episode of restenosis at the anastomosis prompted operative re-exploration, in which additional HGM was found within the specimen.

Jejunal atresia is a well-known congenital malformation with an incidence of 1 per 1000 live births attributed to an in utero ischemic event.¹ Heterotopic gastric mucosa (HGM), gastric tissue present in a location other than the stomach, is a much rarer congenital anomaly. Heterotopic tissue is generally found in the esophagus or within a Meckel’s diverticulum. Identifying both within the same pathologic specimen is rare. Currently, there are <10 reports in existence.² This report outlines a case of jejunal atresia wherein HGM was identified within postoperative pathology evaluation of the specimen. An early episode of restenosis at the anastomosis prompted operative re-exploration, in which additional HGM was found within the specimen.

CASE REPORT

A 2.3 kg black female was born at 35 weeks’ gestation. An ultrasound at 33 weeks’ gestation demonstrated an enlarged proximal small bowel and stomach concerning for intestinal atresia. A contrast study conducted on day of life 1 demonstrated proximal jejunal atresia (Figure 1a) prompting immediate operative exploration. Intraoperative findings included a type 1 atresia 8 cm from the ligament of Treitz. The distal bowel was investigated, revealing no further atretic segments or masses. Resection and anastomosis were performed. The anastomosis was tested and was found to be widely patent. On pathologic microscopic evaluation, sections showed scattered islands of gastric foveolar epithelium and mildly thickened muscularis propria. In conjunction with the clinical assessment, the overall gross and microscopic findings were compatible with gastric heterotopia in a setting of jejunal atresia (Figure 1b).

Figure 1.

(a) X-ray of the chest and abdomen in a neonate, day of life 1. (b) Initial resection specimen, hematoxylin and eosin stain. Normal small bowel with enterocytes (left) and goblet cells transitioning to gastric foveolar epithelium (right), consistent with gastric heterotopia.

On postoperative day 24, the patient developed bilious emesis. An upper gastrointestinal contrast study demonstrated anastomotic narrowing with delayed transit, concerning for partial obstruction. The patient was re-explored, and the anastomosis was found to be stenosed. Additionally, jejunum 2 cm distal to the anastomosis was thickened. Jejunal resection of the previous anastomosis and the thickened distal segment and anastomosis was performed. Again, the anastomosis was tested and found to be patent. On pathologic microscopic evaluation, sections demonstrated residual gastric heterotopia as well as areas of superficial ulceration and granulation tissue. Notably, gastric heterotopia involved one resection margin, likely distal. Postoperatively, the patient recovered quickly. On 3-week follow-up visit, the patient was tolerating her formula diet, stooling, and gaining weight.

DISCUSSION

Intestinal atresia is a congenital anomaly with an incidence of 1.3 to 3.5 per 10,000 live births and a male predominance. Twenty percent of cases are associated with chromosomal anomalies.³ It may manifest in the duodenum (∼60%), jejunum (∼20%), ileum (∼20%), or colon (∼7%–10%). The etiology is hypothesized to be uterovascular accidents causing bowel ischemia, stenosis, and obliteration of the intestinal lumen. Prenatal ultrasound demonstrates dilated proximal bowel and polyhydramnios. Treatment necessarily involves surgical resection and either primary or delayed anastomosis.

HGM in the pediatric small intestine is rare but is recognized in the esophagus, duodenum, jejunum, and colon.⁴ The incidence is unknown but is reported as high as 75% in the esophagus to 13% in a Meckel’s diverticulum.⁵ HGM may be occult, but when it presents clinically, it may do so as bleeding, pain, obstruction, or concurrent with Meckel’s diverticulum.⁶ Generally, when found, these loci are found within the duodenum unless associated with a Meckel’s diverticulum.⁷ HGM has been reported in an intestinal atresia specimen on only six occasions. Thus, the rare result of the pathology report in this case was cause for interest and investigation.

In the case presented, the decision to operate was based upon the patient’s jejunal atresia, and there was no preoperative suspicion of HGM. Once identified in the initial pathology report, the assumption was that the heterotopy was completely resected. The patient’s eventual restenosis was preoperatively attributed to mucosal hyperplasia, a known complication. During reoperation, concern for HGM arose when the distal intestinal segment was found to be thickened. Although not standard for HGM resections, frozen section may have provided definitive evidence for complete resection at the time of reoperation, as the margin was involved on final pathology. For this reason, consideration for postoperative monitoring remains paramount. The longitudinal history of HGM is unknown, and it remains possible that residual HGM may not cause future clinical sequelae.

However, residual HGM may cause obstruction, intussusception, strictures, and perforation.⁸ Few reports are available that give guidance for monitoring after resection. In a similar case,² a patient underwent a technetium scan after resection and was not found to have residual tissue. This patient has remained asymptomatic. In a separate case, a 14-year-old boy developed obstruction from polyps that developed from the heterotopic tissue,⁹ which required laparotomy and resection. Additionally, a case of a neonate with atretic jejunum containing enteric duplication with gastric and duodenal heterotopia resulted in symptoms of acute bowel obstruction 19 years later. Pathology demonstrated mucosal hyperplasia with heterotopic gastric and duodenal tissue at the anastomotic site.¹⁰ What may happen in the future for a patient with residual HGM is unknown. At present, the parents have been counseled regarding possible future complications.

In conclusion, HGM associated with intestinal atresia is a very rare and notable occurrence. This case is particularly noteworthy because restenosis occurred secondary to persistent HGM at the resection margin. Frozen section should be considered in reoperation on these patients. Finally, good clinician-family communication and diligent clinical observation are critical moving forward, as sequelae are unknown.