Risk of Intracranial Extension of Craniofacial Dermoid Cysts.

BACKGROUND

Dermoid cysts are benign lesions lined by keratinizing squamous epithelium that also contain epidermal adnexa (hair follicles, hair shafts, sebaceous glands, and both apocrine and eccrine sweat glands) and mesodermal derivatives (smooth muscle fibers, vascular stroma, nerves, and collagen fibers). Craniofacial dermoid cysts represent approximately 7 percent of all dermoids and have an incidence ranging between 0.03 and 0.14 percent.

METHODS

The authors conducted a single-center, consecutive, nonrandomized comparative case series over a 20-year period of all patients treated surgically for craniofacial dermoid at the Royal Children's Hospital in Melbourne, Australia. Six hundred forty-seven patients had craniofacial dermoids and adequate information to be included in the study. The authors also conducted a thorough review of the literature using the MEDLINE and Embase databases.

RESULTS

Six hundred forty-seven patients amounted to 655 lesions in our case series. The age at surgery ranged from 2 months to 18 years, with an average age of 25.65 months. The depth of the lesions was stratified using a classification system, and the risk of intracranial extension was assessed using these data. Midline nasal lesions are established as high risk by other studies, but frontal, temporal, and occipital lesions were found to be as risky if not more risky for intracranial extension.

CONCLUSIONS

Several classification systems for craniofacial dermoid cysts have used both broader anatomical locations and physical characteristics to group these lesions and identify those warranting preoperative imaging. The authors propose a system using more specific classification of anatomical location to assist in the prompt identification of high-risk lesions and facilitate sound preoperative planning.

CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.