Mucocels are cavities resulting from obstruction of an excretory duct of the paranasal sinus. They are lined with mucosa and filled with mucus, which leads gradually to an expansion and thinning of the surrounding bone structures. The causes are usually previous traumas or previous surgerys of the paranasal sinus. In the majority of cases endonasal surgery is possible. With some exceptions, an extra-nasal approach may be necessary via a 'Killian'- incision or osteoplastic sinus surgery.
We report on a 12-year-old patient with a 5 × 5 cm progressive bony swelling right frontotemporal for 2 – 3 years. A trauma could be elicited 7 years before in the documents of the Children's Hospital. According to the documents, a collision trauma with frontal laceration on the right side had occurred. A fracture, however, was not described at that time.
On magnetic resonance imaging and computer tomography of the paranasal sinuses a laterally filled frontal sinus with thinning of the anterior bony lamella was found. Considering a far laterally located mucocele and the existence of two separate “chambers”, an endonasal approach was not indicated. After detailed discussion within the team, an extranasal, minimally invasive, endoscopic and navigation-assisted osteoplastic sinus surgery was performed via an small lateral incision under the eye brow. Postoperative healing was cosmetically very satisfactory. In a control magnetic resonance tomography 16 months postoperatively, the large lateral recess of the right frontal sinus was found regularily airefilled.
In conclusion, a far-lateral, separated mucocele of the frontal sinus can be managed surgically and cosmetically successful with an minimally invasive, endoscopic but extranasal approach.
