Endoscopic management of a massive nasal osteoma presenting as an orbital abscess

Abstract

1. Case presentation A 13-year-old female with a 1-week history of sinusitis and a 3-day history of right-sided proptosis and diplopia from limited extraocular muscle movement was evaluated in our pediatric emergency department. The patient also had complaints of prior nasal obstruction for several years and had undergone 2 prior adenoidectomies for these complaints. No history of craniofacial trauma was elicited. Computed tomographic scan of the orbit revealed a large abscess involving the superior medial aspect of the orbit, displacing the globe laterally. Also noted was a large, dense, homogenous bony mass essentially involving the entire right nasal cavity, including the ethmoid and maxillary sinuses (Fig. 1). Magnetic resonance imaging showed no intracranial extension. A diagnosis of nasal osteoma with secondary orbital abscess was made, and the patient was taken to the operating room for biopsy of the mass and drainage of the orbital abscess. An external approach was necessary due to the intranasal obstruction from the tumor. The drainage was uncomplicated, and the patient was treated with intravenous ceftriaxone and changed to oral clindamycin. The ophthalmologic service was consulted before discharge, and the patient's vision was within normal limits. Her proptosis persisted after drainage of the abscess, but intraocular pressures were normal. The pathologic results were consistent with an osteoma of the nasal cavity. The patient was therefore scheduled for image-guided endoscopic removal of this mass as well as right medial orbital wall decompression 4 weeks later. At the time of surgery, she was noted to have a massive osteoma of the right nasal cavity, which appeared to originate from the middle turbinate. It was involving the entire nasal cavity, approximating the anterior skull base along its entire length. It also abutted the face of the sphenoid, as well as the lamina papyracea, with thinning and lateral bowing of the lamina papyracea, causing residual mild to moderate proptosis. The mass also involved the entire right maxillary antrum. It was excised endoscopically with the use of a 0° nasal endoscope and various-sized otologic cutting and diamond burs. The mass was “cored out” in an inferior to superior direction and removed in a piecemeal fashion via delivery through the right nostril and nasopharynx. At the end of the procedure, total ethmoidectomy and sphenoidotomy were performed in the standard fashion because they had been significantly distorted by the expansion of this mass. Right medial orbital wall decompression was also accomplished by removal of the lamina papyracea to help reverse her proptosis. The procedure was tolerated well with minimal blood loss. A sinus computed tomographic scan at 6 months postoperatively illustrated resolution of her proptosis with no evidence of recurrence (Fig. 1). The patient was subsequently noted to have developed right-sided synechiae and polypoid changes for which she underwent resection at 13 months postoperatively.