Endoscopic Submucosal Dissection of Seborrheic Keratosis-Like Lesion of the Esophagus: A New Entity?

Abstract

Seborrheic keratosis, one of the most common lesions of the epidermis, is rarely seen on mucosal surfaces. We report a case of a distinctiveepithelial neoplasm of the esophagus showing close resemblance to seborrheic keratosis that was resected with endoscopic submucosaldissection. A 65-year-old patient’s previous esophageal biopsy showed suspicious low grade dysplasia and the patient was referred for endoscopicsubmucosal dissection of a flat lesion in the mid-esophagus. Macroscopic examination revealed a well circumscribed, pigmented and elevatedlesion with a diameter of 20 mm. Microscopically, the lesion was well circumscribed, with plaque-like elevation, and showed hyperkeratosis,acanthosis, and papillomatosis. Broad coalescing solid sheets and interconnecting trabeculae of basaloid cells were the consistent featurethroughout the lesion. Squamous eddies and occasional central keratinization were present. Mitotic activity and koilocytes were not identified.Immunohistochemically, the lesion showed diffuse nuclear positivity with p63 and negativity with p16. Ki-67 index was confined to the basalcell layer. With the help of histopathologic and immunohistochemical findings, we diagnosed this morphologically benign case as “seborrheickeratosis-like lesion of the esophagus”. It should be kept in mind that seborrheic keratosis-like lesions might be rarely seen on mucosal surfacessuch as the esophagus. Endoscopic submucosal dissection is a new, curative, and safe endoscopic resection technique in en-bloc resectionof superficial esophageal lesions. To our knowledge, this is the first case of the aforementioned lesion in the esophagus being resected withendoscopic submucosal dissection.