PhiliPPine Journal of otolaryngology-head and neck Surgery Vol. 22 noS. 1 & 2 January –June; July – december 2007 FROM THE VIEWBOX PhiliPPine Journal of otolaryngology-head and neck Surgery 35 An ossifying fibroma is a monostotic lesion that occurs in craniofacial bones. It usually presents as a painless well-circumscribed, slow-growing mass in the 3rd and 4th decade. It is a benign fibro-osseous lesion that is part of the bigger spectrum of fibro-osseous lesions which includes fibrous dysplasia, juvenile active ossifying fibroma, psammomatous ossifying fibroma, and extragnathic ossifying fibroma of the skull. An ossifying fibroma, because of its well-circumscribed nature, lends itself to surgery better than does fibrous dysplasia. Simple enucleation is usually sufficient for ossifying fibromas whereas curettage is probably better suited for fibrous dysplasia. Radiographically, it is seen as a well-demarcated radiolucency in the mandible or maxilla, more common in the former than the latter. It typically measures anywhere from 1 to 5 cm. There may or may not be a central opacity or calcification, depending on the maturity of the lesion. An immature lesion may present as completely radiolucent whereas a mature lesion may be completely radiopaque, although most lesions demonstrate varying degrees of radiopacity. The images above show two samples of the same lesion on opposite sides of the spectrum. Both are well-circumscribed but one is relatively radiolucent while the other is floridly sclerotic. Is there a pathognomonic finding on x-ray? Unfortunately, there is not one single finding that will distinguish an ossifying fibroma from other fibro-osseous lesion. Does it matter? Yes. X-rays will lead the clinician to one diagnosis or the other and help plan the intended surgery. Johanna Patricia A. Cañal, MD, MHA Department of Radiology College of Medicine – Philippine General Hospital University of the Philippines Manila The Spectrum of Ossifying Fibroma Philipp J Otolaryngol Head Neck Surg 2007; 22 (1,2): 35 c Philippine Society of Otolaryngology – Head and Neck Surgery, Inc. ReFeRenceS: Dahnert, W. Radiology Review Manual. 5 ed. Lippincott, Williams & Wilkins. Philadelphia 2003. Gannon FH & Thompson LDR. Ossifying Fibroma of the Jaw. Ear, Nose & Throat Journal, (online) July 2004. Available from http://www.entjournal.com. Voytekt M, Ro JY, Edeiken J & Ayala AG. Fibrous dysplasia and cemento-ossifying fibroma: a histologic spectrum. Am J Surg Path. Vol. 19, No. 7. 1995. Lee, KJ. Textbook of Otolaryngology and Head and Neck Surgery. Appleton & Lange. New York. 1989. Toyosawa S, Yuki M et al. Ossifying fibroma vs fibrous dysplasia of the jaw: molecular and immunological characterization Correspondence: Johanna Patricia A. Cañal, MD, MHA Department of Radiology Philippine General Hospital Taft Ave., Ermita, Manila 1000 Telefax (632) 523-4372 Email:joie_canal@yahoo.com Reprints will not be available from the author.