Intraosseous Epidermoid Cyst: a Case Report

Background: Epidermoid cysts are benign lesions that occur throughout the body. Their development in the oral cavity is extremely rare. Intraosseous epidermoid cysts of the jaw are even rarer and difficult to distinguish from other lesions. For this reason, we would like to draw the attention of practitioners to this pathology as a differential diagnosis through the presented clinical case. Methods: This study presents an unusual case of a type of epidermoid cyst in an edentulous maxilla. A 70-year-old man was referred to the Maxillofacial Surgery Division at the University Multiprofile Hospital for Active Treatment and Emergency Medicine "N. I. Pirogov", Sofia, Bulgaria, for a single radiolucent area in his anterior maxilla. The patient underwent surgery to extract the cyst. Results: Based on the clinical and radiographic evaluation, a preliminary diagnosis of dentigerous residual cyst was made. The histopathological examination of the hematoxylin and eosin stained sections revealed an epidermoid cyst based on the observed thick keratin layer resembling epidermis together with the stratified squamous epithelium lining with many layers of sheaves of orthokeratin. Conclusions: This report presents an uncommon case of an intraosseous epidermoid cyst occurring without a history of maxillary trauma. Although intraosseous epidermoid cysts are extremely rare in jaws, they should be considered in the differential diagnosis of radiolucent lesions.