Abstract
A slow-growing frontal sinus osteoma has been followed up since the year 2001 by clinical, endoscopic, and radiological examination in the Department of Otolaryngology, New Medical Centre Specialty Hospital, Abu Dhabi, for 10 years until the year 2010. The last computed tomography scan of paranasal sinuses was done on April 5, 2010, which revealed increasing size of the osteoma by 38.1 mm; and it has become symptomatic. No specific cause of the sudden change of growth of the osteoma could be evaluated from the history and clinical examination. There was an increase in the frequency of headache and feeling of pressure in the forehead. Choice of surgical approach was difficult in this popular era of endonasal endoscopic sinus approach. A great deal of effort was made after reviewing the literature and consultation with the radiologist and neurosurgeon to accept the bicoronal osteoplastic flap approach. A broad-based posterior frontal sinus is found to be ideal for external approach.
1
Introduction
Frontal sinus osteomas are mostly asymptomatic, but may precipitate chronic sinusitis, mucocele, or chronic headache depending on the site, size, and duration of the tumor. A symptomatic large frontal sinus osteoma arising from the posterior wall of the sinus may pose a surgical dilemma in this era of image-guided endoscopic sinus surgery (IGESS). The best surgical approach to ensure complete and safe removal of the posteriorly based frontal osteoma is less clear cut. This article deals with a large symptomatic frontal osteoma of 10 years’ duration arising from the posterior wall of the sinus that has been excised by osteoplastic flap surgery approach. Review of available English literature fails to show such report of frontal sinus osteoma that has been followed regularly with x-ray films and computed tomography (CT) scans for 10 years in the same medical center until it became symptomatic. The aim of this article is to emphasize that an external approach is still an approach of choice in the surgical management of such a type of osteoma.
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Case history
SB, a 40-year-old Indian woman (file no. A66799/1), was first examined in the Neurology Department of the New Medical Centre Specialty Hospital, Abu Dhabi, for her complaints of headache. X-ray of paranasal sinuses (PNS) done at that time revealed left-sided frontal osteoma. The patient was then referred to the Department of Otolaryngology; and CT of PNS was done on May 12, 2001, which further confirmed the presence of ivory osteoma. Since then, the patient was followed up in the ENT Department regularly, wherein the next CT scan PNS was done in 2005. There was no radiological change in the size or shape of the tumor. Her subsequent visits to the department were uneventful, and it was more of a regular follow-up. She visited the department on March 27, 2010, with complaints of headache and watering from the eyes. The frequency of her headaches increased, and she started feeling a sensation of pressure in her head. The last CT scan PNS was done on April 5, 2010; and it was found that the size of the osteoma increased by 38.1 mm and that it was attached to the posterior wall of the sinus with a broad base ( Fig. 1 ). There was no positive history to explain the sudden change in the size of the tumor. The neurosurgeon’s opinion was taken regarding the surgical excision. Keeping in mind the increasing size of the osteoma and the increasing frequency of the headaches, we had decided to take up the case for surgical excision. The size of the tumor and its attachment to the posterior wall made us believe that the external approach was more appropriate for this case. She was operated on April 18, 2010, in our hospital. Histopathology showed a tumor constituted by mature lamellar bone; no haversian canal was seen, and no fibrous stroma was seen. The histology was consistent with osteoma ( Fig. 2 ).
2.1
Surgical approach
The osteoplastic flap approach used in our case has a classic bicoronal flap with an incision starting from the tragus on one side to the tragus on the other side and with flap incision placed 2 cm posterior to the hairline. Anteriorly, the flap was extended up to the supraorbital ridge, preserving the supraorbital vessels and supraorbital-supratrochlear nerve in the scalp flap. After using a template of the frontal sinus from the x-ray Caldwell view of the sinuses, surface marking of the upper end of the frontal sinus was performed. A separate pericranial incision was then made just above the upper margin of the frontal sinus, and the pericranial flap was elevated up to the supraorbital ridge. Hereafter, instead of making a classic osteoplastic flap, a small bony window was made using a cutting burr. The bony window was made at the upper end of the marked frontal sinus and around the sinus wall to help in its elevation. The removed bony window from the outer table of frontal sinus was preserved in saline. The edges of bone cuts were made beveled. The osteoma was exposed and was found to be arising from the posterior wall of the sinus ( Fig. 3 ). Mucopus was seen within the sinus and suctioned out. The tumor was drilled out using both cutting and diamond burrs, leaving behind the thin posterior wall. The remaining mucosa was removed. The frontal recess area was found to be blocked completely by the tumor, and no further attempt was made to obliterate the sinus. After clearing the frontal sinus of the osteoma and sinus mucosa, the bony window was replaced and positioned by suturing to the cut bone above and pericranium below ( Fig. 4 ). The wound was closed in 2 layers after placing a suction drain. Last follow-up done on June 10, 2010, showed well-healed osteoplastic flap incision.
