Endoscopic-guided Excision of a Midline Forehead Dermoid

Endoscopic excision of benign forehead masses in children aims to avoid conspicuous scarring and disfigurement. In this video, we'll present our experience with endoscopic guided removal of an intraosseous dermoid located in the mid forehead. This infant presented at 10 months of age with a firm non-mobile mass in the mid forehead that was noted by his parents. He was entirely asymptomatic due to the conspicuous location of the mass and his dark complexion. We felt he would be a good candidate for endoscopic removal. CT scan with bone windows showed a 1 centimeter mass located in an intraosseous pocket in the mid forehead. On the view to your right, the mass appears to be encased by thick periosteum. A pediatric general surgeon and a head and neck surgeon with extensive experience in facial plastics collaborated to perform the procedure at 18 months of age. The locations of the lesion and of the incision are marked. The endoscope attached to the tissue retractor will be taking a straight approach towards the lesion. A short vertical incision is made in the midline, approximately 2 centimeters above the hairline. Cautery is used to deepen the incision through subcutaneous tissue, galia, and periosteum to the level of the bone. A periosteal elevator is used to strip the periosteum off the bone, approximately 1 centimeter in all directions. A curved elevator is then used to create a subperiosteal tunnel in the midline starting at the incision and advancing towards the lesion. The periosteum and frontalis muscle are tented up as the elevator advances. The endoscope is now advanced through the incision towards the lesion. The periosteal elevator is introduced under the scope. All instruments will be introduced in this fashion. The periosteum has been dissected off the bone, however, the dermoid is hidden by a layer of severely adherent, thickened sclerotic periosteum. The rim of the bone crater containing the dermoid is reached. Significant force is required to elevate the adherent calcified periosteum and expose the dermoid. Gradual deliberate dissection is continued until the crater containing the dermoid is clearly seen. A sharp curved curette is used to initiate excision of the dermoid. A blunt, right angled curette is used to reach deeper into the crater. The extruded contents of the dermoid are seen. Dissection is now carried out between the bone and the dermoid wall to achieve complete excision. The wall of the dermoid is being successfully excised and removed using a 5 millimeter Maryland grasper. residual dermoid wall is seen in the now empty crater. A curved, sharp curate succeeds in removing the last portion of the dermoid. The crater is suctioned and complete removal of the dermoid is confirmed. The edges of the bone crater are rasped to obtain a smooth contour. The surgical site is irrigated and suctioned to remove debris and small hairs. Bone wax is applied to the crater. This aids hemostasis and fills the bony defect. The excess bone wax is removed. Any hair introduced through the incision is removed. A final look confirms hemostasis. The deep tissues are not approximated. The skin is closed with 3 interrupted sutures of 4 ochromic. The child's appearance 3 days after surgery is shown here. His parents were highly satisfied with the result.