Frontotemporal dermoid cyst with incomplete dermal sinus tract in an adult: A case report

Background Non-midline supratentorial dermoid cyst with dermal sinus tract has been rarely reported especially in adults. We recently experienced a noteworthy patient with frontotemporal dermoid cyst with incomplete dermal sinus tract. Case description A 43-year-old female presented with recurrent subcutaneous mass in the left superolateral orbital region. She had a history of active bronchial asthma, which precluded her from contrast-enhanced imaging studies. Plain imaging studies showed a subcutaneous mass which was continuous with an intrasylvian fissure mass by a tract in the sphenoid ridge and the lesser wing of the sphenoid bone. Frontotemporal craniotomy was performed to reset the mass and the tract. Intraoperative finding showed no intradural tumor components. Extradural component was carefully removed focusing attention on the frontal branch of the facial nerve. The pathology was consistent with dermoid cyst and dermal sinus tract. Postoperatively, she had mild facial palsy of the corrugator supercilii (House and Brackmann Grade II). She was discharged home with modified Rankin scale 1. Conclusion Dermoid cyst needs to be included in the differential diagnosis of adult-onset subcutaneous mass in the frontotemporal regions. After thorough imaging studies for the presence and extent of the sinus tract, the symptomatic lesion should be excised completely once and for all.