Heterotopic pancreas in the rectum

Heterotopic Respiratory Mucosa in the Rectum: An Unusual Type and Site of Heterotopia in the Gastrointestinal Tract

Although pancreatic and gastric heterotopias are common findings in the gastrointestinal tract, heterotopic respiratory mucosa (HRM) in the rectum is extremely rare and has only been reported twice previously. We are presenting, to our knowledge, the third case of HRM in the rectum. A 56-year-old man with a history of chronic diarrhea presented for diagnostic colonoscopy, where he was found to have a rectal subepithelial nodule. He was subsequently referred to a tertiary medical center for further evaluation with rectal endoscopic ultrasound. Endoscopically, the nodule was hypoechoic, 2 to 3 mm in size, located in the submucosa, and did not appear to invade the muscularis propria. An uncomplicated endoscopic submucosal resection was subsequently performed. Microscopically, the nodule showed a multicystic complex lesion located in the submucosa, lined by ciliated pseudostratified columnar epithelium and surrounded by thin to moderately thick smooth muscle bundles and multiple lobules of seromucinous glands. There was associated acute and chronic inflammation. The rectum overlying the subepithelial lesion was lined by congested and edematous colonic mucosa and demonstrated no connection with the underlying cystic lesion. Immunohistochemical stains showed positive p63 basal cell staining in the respiratory epithelium of the lesion, while CDX2, TTF-1, and estrogen receptors were all negative. HRM is a benign nonneoplastic lesion with unclear etiology. Pathologists and gastroenterologists should be aware of this entity and consider it in their differential diagnosis for a subepithelial nodule in the rectum, keeping in mind that neoplastic processes can also develop in this location.

Ectopic pancreas in mediastinum: report of 2 cases and review of the literature

Ectopic pancreas in mediastinum is uncommon. In this paper 2 cases of patients who had large cysts or cystic-solid masses containing pancreatic tissue in mediastinum were reported. Although the clinical presentations of these 2 patients were nonspecific, some specific characteristics in the imaging findings were discovered, which will be helpful for the diagnosis. However, the final diagnosis depends on pathologic examination.

Heterotopic respiratory mucosa in the rectum: a first case report

A 50-year-old Japanese woman consulted our hospital complaining of hematochezia. Colonoscopic examination showed Borrmann type 1 rectal carcinoma in the lower rectum, which was later demonstrated to be mucinous adenocarcinoma of Dukes' class A. Along with carcinoma, there was a small sessile polyp with a central depression that mimicked a submucosal tumor. Histologically, the polyp demonstrated tubular structures that coursed from the top of the polypoid surface to the deep submucosa. The tubular structure was 6 mm in length and showed abortive dichotomous branching. It was mainly lined by ciliated pseudostratified columnar to more cuboidal epithelium. Along with the tubular structure, there were bundles of smooth muscle cells and lobules of seromucinous glands. There was no cartilage. The pathological diagnosis was heterotopic respiratory mucosa (HRM) arising in the rectum. To our knowledge, this is the first reported case of HRM in the rectum.

Pancreatic diseases in children

The main congenital anomalies of the exocrine pancreas are reviewed, and several generalized and isolated hereditary pancreatic diseases are discussed. In contrast with adults, the most frequent causes of acute pancreatitis are viral infection, drug induction, and trauma. The dissimilarities between pediatric and acute and chronic pancreatitis are emphasized.