Ectopic respiratory mucosa in the skin associated with skeletal malformation and polydactyly

Heterotopic respiratory mucosa as a potential source of ectopic Sonic hedgehog (SHH) in the development of complex radial polydactyly and ulnar dimelia

We report eight cases of complex radial polydactyly and/or ulnar dimelia each with a fistulous lesion of heterotopic respiratory mucosa in radial-anterior skin ranging from shoulder to wrist. Although speculative, the coincidence of these rare conditions suggests a mechanistic relationship.

Cutaneous ectopia of lung, located on back and neck: Hitherto undescribed presentation

Ectopia is defined as the presence of a normal-appearing tissue in an abnormal location, where it is not normally found. In the literature, it is also referred to as heterotopia and is described as choristoma when it forms a mass. Lung tissue ectopia is a rare anomaly and is characterized by the presence of mature lung tissue comprising well-formed bronchi, bronchioles, and alveoli at an abnormal location. Occurrence of ectopic lung tissue in the skin is an extremely rare entity and the diagnosis is mostly established by histopathologic examination. This report documents a rare occurrence of cutaneous ectopic lung tissue at two locations (neck and back). Cutaneous ectopia at multiple sites has not been described in the literature till date.

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.

The first Korean case of cutaneous lung tissue heterotopia

Cutaneous lung tissue heterotopia is a very rare disorder where mature lung tissues develop in the skin. This is only the second known report of cutaneous lung tissue heterotopia, with the first by Singer et al. in 1998. A newborn infant had a hemangioma-like, freely movable mass connected to the anterior aspect of the sternal manubrium. Pathologic findings showed mature lung tissues with bronchi, bronchioles, and alveoli through the dermis and subcutis, and it was diagnosed as cutaneous lung tissue heterotopia. Cutaneous lung tissue heterotopia is hypervascular, so grossly it looks like a hemangioma. It can be differentiated from pulmonary sequestration, teratoma, bronchogenic cyst, and branchial cleft cyst by histology and the location of the mass. We describe the clinical, radiologic, and pathologic findings of a cutaneous lung tissue heterotopia, the first reported in Korea.