Esophageal submucosal gland duct adenoma: characteristic EUS and histopathologic features

Modified endoscopic submucosal tunnel dissection for large esophageal submucosal gland duct adenoma: A case report

BACKGROUND

With the recent improvement of endoscopic techniques, endoscopic ultrasound-guided fine needle aspiration and endoscopic submucosal tunnel dissection (ESTD) have been widely used for accurate diagnosis and dissection acceleration of esophageal tumors.

CASE SUMMARY

We used a modified submucosal tunnel technique during endoscopic en bloc resection in a 58-year-old man with large esophageal submucosal gland duct adenoma (ESGDA). During modified ESTD, the oral end of the involved mucosa was cut transversely, followed by a submucosal tunnel created from the proximal to the distal end, and the anal end of the involved mucosa blocked by the tumor was incised. As a result of retaining submucosal injection solutions using the submucosal tunnel technique, it was possible to reduce the amount of injection required and increase the efficiency and safety of dissection.

CONCLUSION

Modified ESTD is an effective treatment strategy for large ESGDAs. Single-tunnel ESTD appears to be a time-saving procedure compared with conventional endoscopic submucosal dissection.

Submucosal gland neoplasms of the esophagus: an update and review

Submucosal glands (SMGs) present throughout human esophagus with clusters at either the upper third or lower third of the organ. SMGs tend to atrophy with age, and neoplasms arising in these glands are rare. In order to bring convenience to diagnosis, we summarize the histopathologic characteristics of all esophageal submucosal gland tumors (SGTs). Due to the morphological similarity, the nomenclature of salivary tumors is adopted for SGTs. However, there is great confusion about the definition and histogenesis of these tumors, especially the malignant subtypes. In the literature, esophageal mucoepidermoid carcinoma and adenoid cystic carcinoma usually adjoin the surface squamous epithelium and coexist with intraepithelial neoplasia or invasive squamous cell carcinoma (SCC). In addition, the typical gene alterations of salivary tumors have not been reported in these SGTs. Therefore, we propose to apply stringent diagnostic criteria to esophageal SGTs so as to exclude mimickers that are SCCs with various degree of SMG differentiation.

Esophageal submucosal gland duct adenoma: a clinicopathological and immunohistochemical study with a review of the literature

Esophageal submucosal gland duct adenoma (ESGDA) is a rare tumor. The clinicopathological features of the ESGDA and its precursor lesion have not been comprehensively evaluated. In this study, we aimed at delineating the clinicopathological features of the ESGDA and cyst formation of the esophageal submucosal gland duct (ESGD), as well as their correlations and clinical implications. We identified three cases of ESGDA and 16 cases of cyst formation of the ESGD among 786 endoscopic mucosal resection specimens over a 7-year period. The median patient age was 58 years with a male predominance. These lesions were small submucosal bulges locating at the lower esophagus with a size no more than 1 cm. The main microscopic changes of these lesions included content retention, multilayered epithelium or papillary folds of the ESGD and inflammatory cell infiltration, acidophilic degeneration, hyperplasia or atrophy of the acini. The included cases generally showed moderate to severe microscopic esophagitis. The ESGDA was mainly consisted by multiple glandular cysts covered by two layers of cells. Immunohistochemical results showed that the luminal duct lining cells and basal cells were positive for CK7 and p63, respectively. Both of the two layer cells were positive for HMWCK and negative for CK20, p53, CDX2, MUC5AC, MUC6, MUC2 and MUC1. The proliferation index was very low (1%). The diagnostic criteria of the ESGDA were proposed and, the differential diagnosis was discussed. Cyst formation of the ESGD is considered to be the precursor lesion of the ESGDA, because they have overlapping clinicopathological features with progressive relationship. In addition, the ESGDA have close connection with advance of the GERD and, probably, an increased risk of carcinoma.

Esophageal gland duct adenoma: immunohistochemical comparison with the normal esophageal gland and ultrastractural analysis

Esophageal gland duct adenomas are extremely rare tumors. Here, we report the case of a 75-year-old Japanese man who had undergone total gastrectomy for advanced gastric cancer. Esophageal gland duct adenoma was incidentally found in the lower esophagus. It appeared to be detached from the site of gastric cancer and was well demarcated without a capsule. Histologic analysis revealed papillary and cystic structures mainly comprising eosinophilic cells with minimum nuclear atypia. Immunohistochemical analysis revealed that the tumor were diffusely positive for the S100 protein with preserved alpha-SMA-positive myoepithelial cell layers and a characteristic cytokeratin expression pattern similar to that in normal esophageal gland ducts (CK5/6+++, CK7+++, CK17+, CK18+, CK19+++, CK20-, HMWCK+++). In addition, differentiation into the terminal duct was confirmed by a combination of mucin staining and immunohistochemical and ultrastructural examinations. This is the first report that refers to the ultrastructural findings of an esophageal gland duct adenoma and describes terminal duct differentiation. We believe that the possibility of an esophageal gland duct adenoma should be considered when diagnosing a ductal or glandular lesion of the esophagus.