Head and Neck, Odontogenic keratocyst

Odontogenic keratocysts are rare, benign, and potentially locally aggressive developmental cystic neoplasms of odontogenic epithelial origin. The neoplasms are often associated with Gorlin/nevoid basal cell carcinoma syndrome. A mutation in the PTCH gene is found in patients with this syndrome. Sections show fragments of cyst wall lined by an epithelium that has characteristic findings of an odontogenic keratocyst in areas. The epithelium is 6 to 8 cells thick, with a hyperchromatic and palisaded basal cell layer, and corrugated parakeratotic surface. The epithelial lining lacks rete ridges, and is keratinizing. In other areas, the lining is hyperplastic and reactive appearing. Hyalin bodies or pink to basophilic lamellar bodies are formed by the cyst lining epithelium and indicate the odontogenic origin of a cyst.