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.

Massive duodenal variceal bleed; complication of extra hepatic portal hypertension: Endoscopic management and literature review.

Bleeding from duodenal varices is reported to be a catastrophic and often fatal event. Most of the cases in the literature involve patients with underlying cirrhosis. However, approximately one quarter of duodenal variceal bleeds is caused by extrahepatic portal hypertension and they represent a unique population given their lack of liver dysfunction. The authors present a case where a 61-year-old male with history of remote crush injury presented with bright red blood per rectum and was found to have bleeding from massive duodenal varices. Injection sclerotherapy with ethanolamine was performed and the patient experienced a favorable outcome with near resolution of his varices on endoscopic follow-up. The authors conclude that sclerotherapy is a reasonable first line therapy and review the literature surrounding the treatment of duodenal varices secondary to extrahepatic portal hypertension.

A decrease in anandamide signaling contributes to the maintenance of cutaneous mechanical hyperalgesia in a model of bone cancer pain.

Tumors in bone are associated with pain in humans. Data generated in a murine model of bone cancer pain suggest that a disturbance of local endocannabinoid signaling contributes to the pain. When tumors formed after injection of osteolytic fibrosarcoma cells into the calcaneus bone of mice, cutaneous mechanical hyperalgesia was associated with a decrease in the level of anandamide (AEA) in plantar paw skin ipsilateral to tumors. The decrease in AEA occurred in conjunction with increased degradation of AEA by fatty acid amide hydrolase (FAAH). Intraplantar injection of AEA reduced the hyperalgesia, and intraplantar injection of URB597, an inhibitor of FAAH, increased the local level of AEA and also reduced hyperalgesia. An increase in FAAH mRNA and enzyme activity in dorsal root ganglia (DRG) L3-L5 ipsilateral to the affected paw suggests DRG neurons contribute to the increased FAAH activity in skin in tumor-bearing mice. Importantly, the anti-hyperalgesic effects of AEA and URB597 were blocked by a CB1 receptor antagonist. Increased expression of CB1 receptors by DRG neurons ipsilateral to tumor-bearing limbs may contribute to the anti-hyperalgesic effect of elevated AEA levels. Furthermore, CB1 receptor protein-immunoreactivity as well as inhibitory effects of AEA and URB597 on the depolarization-evoked Ca(2+) transient were increased in small DRG neurons cocultured with fibrosarcoma cells indicating that fibrosarcoma cells are sufficient to evoke phenotypic changes in AEA signaling in DRG neurons. Together, the data provide evidence that manipulation of peripheral endocannabinoid signaling is a promising strategy for the management of bone cancer pain.