Esophageal Adenoid Cystic Carcinoma Treated by Endoscopic Submucosal Dissection

Abstract

Introduction: Adenoid cystic carcinoma (ACC) is a common malignancy of the salivary gland, oropharynx, and bronchi, but is a rare occurrence in the esophagus. Esophageal ACC accounts for less than 0.1% of esophageal malignancies. Previous case reports of esophageal ACC report treatment plans which include esophagectomy. We report a case of primary proximal esophageal ACC and demonstrate successful endoscopic submucosal dissection (ESD) for en bloc removal of ACC of the esophagus. Case Presentation: A 49-year-old Hispanic woman presented with complaints of dysphagia, left subcostal pain, and vomiting. Upper endoscopy demonstrated a 2-cm, smooth, non-ulcerated subepithelial mass found 20 cm from the incisors along the posterior wall of the esophagus. Initial biopsies demonstrated a pathological diagnosis of submucosal neoplasm favoring minor salivary gland origin. Pathologic evaluation at tertiary referral center established the diagnosis of ACC with immunohistochemical stains demonstrating positivity for CK7, actin, p63, and S100. The tumor cells also formed small tubules or solid cords with angulated hyperchromatic nuclei consistent with ACC. CT scan demonstrated a 1.2 x 1.6 cm mass arising from the posterior wall of the proximal esophagus near the thoracic inlet, without any associated lymphadenopathy. Endoscopic ultrasound demonstrated the submucosal lesion. ESD was performed using a 1.5-mm ball point needle knife after the lesion was injected with hyaluronic acid. En bloc resection of the mass was performed; however, pathology demonstrated involvement of the vertical margin of the 1.7 x 1.3 x 0.9 cm well-differentiated ACC (pT1b). Despite post-procedure steroids, the patient developed dysphagia 2 months after ESD and required dilation with a 14-mm savory bougie for a benign stricture associated with ESD. Biopsies taken at that time were benign. Conclusion: Adenoid cystic carcinoma is an exceedingly rare tumor of the esophagus. Radical excision with esophagectomy has generally been regarded as the treatment of choice. We describe resection of ACC with ESD, but because of involved margins the patient is in an aggressive surveillance program. ESD should be considered in the treatment algorithm for superficial adenoid cystic carcinoma of the esophagus.