Surgical excision is the treatment of choice in any localization. Surgically remove dermoid cysts.
In some patients, surgery should be performed even more carefully than usual because the fatty content of the cyst may spread to the surrounding tissues or anatomic structures, especially if the cyst is infected with bacteria. The spread of these contents can cause foreign body reactions and severe complications.
Minimally invasive surgical techniques have been successful in removing dermoid cysts from difficult locations, such as those on the tongue or the floor of the mouth. Intralingual dermoid cysts lead to lingual motility defects and speech problems. These cysts should be surgically removed to restore normal lingual function and to correct speech problems.
Intracranial, intramedullary, and ovarian dermoid cysts are difficult to treat. Sophisticated neurosurgical or gynecologic surgical techniques are often needed to remove the dermoid cyst and prevent possible complications. High-definition fiber tracking guidance may be beneficial in the resection of an intraparenchymal dermoid cyst by means of a minimally invasive endoscopic port. 
In some patients with dermoid cysts on the forehead and brow, successful excision with endoscopy-assisted surgery have been described.  In the reported cases, no complications (eg, paresthesia or numbness on the scalp) occurred. The absence of visible scarring is an additional advantage of endoscopy-assisted surgery.
Angular dermoid cyst excision using an eyelid crease approach may yield excellent cosmesis.  External angular dermoid cysts can be excised using a minimally invasive subcutaneoscopic technique that involves placing incisions above the hairline to avoid scarring on the face. 
Frontozygomatic removal through a blepharoplasty incision has been advocated for frontozygomatic dermoid cysts. 
Several possible complications of spontaneous or posttraumatic rupture and surgical procedures have been described. In patients with a ruptured spinal dermoid cyst, fatty droplets can disseminate in the cerebrospinal fluid or in a dilated central canal of the spinal cord. In other patients, subarachnoid and ventricular fat dissemination can occur after the cerebellopontine angle dermoid cyst is resected. Spinal subdural abscesses are a possible complication because of the bacterial infection of spinal dermoid cysts in a dermal sinus tract. A ruptured intracranial dermoid cyst be an incidental finding on an MRI performed for other purposes or because of a persistent headache. 
Pay special attention to intralingual dermoid cysts because deglutition and speech problems may occur.
Nasal dermoid cysts in a nasal tip location are rare, but they may produce social and psychologic problems in children. 
Malignant transformation is an unusual complication that may occur in patients with long-standing dermoid cysts. Carcinomatous transformation to a squamous cell carcinoma is described in sublingual and intra-abdominal dermoid cysts, most often dermoid cysts of the ovary. Metastatic malignant melanomas arising from dermoid cysts have been reported in the literature.