A Case of Ossifying Fibroma in the Frontal Sinus with an Intraorbital Cyst

<p>Ossifying fibroma (OF) is a benign fibrous bone neoplasm that is classified as a fibro-osseous lesion, similar to fibrous dysplasia. Here, we describe a rare case of OF in the frontal sinus. The patient was a 45-year-old woman who presented with redness and swelling extending from the right anterior forehead to the right eye, with significant antero-inferior deviation of the eyeball, complicated by diplopia. Computed tomography of the sinus revealed a mass lesion with mottled calcifications in the right frontal sinus, as well as a cystic lesion extending from the frontal sinus into the orbit. The patient did not consent to total resection via anterior skull base surgery. Therefore, after confirming the diagnosis through biopsy, the cystic lesion was removed from the temporal region by opening the lateral portion of the frontal bone, taking into consideration the location of the cyst and cosmetology. At present, at over 2 years since surgery, there has been no evidence of OF enlargement or recurrence of ocular symptoms or infection.</p><p>There are no widely accepted guidelines for treatment of OF, particularly in cases involving the frontal sinus, where surgical resection is limited by the complicated anatomy of the anterior skull base and orbital wall. However, in cases in which the tumor size does not rapidly increase, watchful follow-up is also a treatment option. The location and size of OF are crucial factors in determining the feasibility of complete resection. Moreover, a comprehensive understanding of the characteristics of fibro-osseous lesions, including OF, is required to formulate an individualized treatment plan in collaboration with doctors from other departments. Factors including surgical invasiveness and approaches and expected symptoms and risks should also be considered carefully.</p>