Fibrous dysplasia in the retropharyngeal area.

Abstract

More fibro-osseous lesions originate in the bones of the extremities than in the craniomaxillofacial bones, scapula, and ribs, which are rarely involved. Fibro-osseous lesions that decrease the quality of life should be treated surgically. We report the case of a fibro-osseous lesion that caused globus pharyngeus and dysphagia. We discuss the clinical radiologic, and histopathologic features of this case as well as the removal of this unusual lesion by Doppler ultrasound-guided surgery. To the best of our knowledge, no other case of a fibro-osseous lesion in the retropharyngeal area has been reported in the literature.

Introduction

The term fibro-osseous lesion applies to a group of non-specific tumors in which medullary bone is replaced by collagen, fibroblasts, and varying amounts of osteoid or calcified tissue. (1-4) These rare, benign tumors of unknown etiology account for approximately 2.5% of all bone tumors. (3) The most common types of fibro-osseous lesions are fibrous dysplasias and ossifying fibromas, which have similar histologic characteristics. Fibro-osseous lesions originate much more frequently in the bones of the extremities, especially the tibia and phalanx, than in the craniomaxillofacial bones, scapula, and ribs, which are rarely involved. (5-7) They usually present as expansile, centric tumors arising from the medullary part of the bones; acentric types at the surface of bones are extremely rare. (2)

We describe the case of an unusual, acentric fibro-osseous lesion that caused globus pharyngeus and dysphagia. We discuss the clinical, radiologic, and histopathologic findings in this case, as well as the Doppler ultrasound-guided surgical removal of the lesion.

Case report

A 29-year-old man presented for evaluation of a retropharyngeal mass that had arisen 6 months earlier. His symptoms included globus pharyngeus and dysphagia; he was otherwise healthy. Physical examination revealed that the 3 x 4-cm mass was located on the posterior pharyngeal wall opposite the tongue base. It was protuberant, hard, immobile, and nontender. The overlying mucosa was healthy, without any erosion or ulceration. No accompanying abnormality was detected on endoscopic examination of the nasopharynx, hypopharynx, and larynx, and no palpable mass was found on the neck. Both computed tomography (CT) and magnetic resonance imaging (MRI) (figure 1) of the cervical region showed an ossified, heterogenous, and well-demarcated mass in front of the second cervical vertebra at the right side of the midline, close to the vertebral and internal carotid arteries. Bilateral intra-arterial digital subtraction angiography of the carotid arteries did not detect any feeding vessel.

[FIGURE 1 OMITTED]

The fibro-osseous lesion was excised via a transoral approach under general anesthesia. A vertical incision was made on the overlying mucosa parallel to the long axis of the lesion. The mucosa was elevated over the mass and dissected under the microscope. The lesion was located in front of the upper cervical vertebrae just medial to the right tonsillar fossa. Because the lesion's posteromedial and posterolateral margins were close to the vertebral and right carotid arteries, respectively, the dissection continued under the guidance of mobile Doppler ultrasonography. After all of the margins were carefully exposed, the lesion was excised without causing any damage to vertebral and vascular structures. Because the transoral approach provided adequate exposure, no other surgical manipulation or incision was required. The mucosal incision was primarily closed by absorbable sutures. The patient experienced no perioperative morbidity and required no medication other than an analgesic.

Histopathologic examination of the surgical specimen showed that it was made up of immature trabeculae of osteoid in a fibrocellular and myxoid stroma (figure 2). The pathologist reported the lesion as a fibrous dysplasia. At the 14-month follow-up, the patient remained asymptomatic and exhibited no evidence of recurrence.

[FIGURE 2 OMITTED]

Discussion

Inflammatory masses and neurovascular tumors are common in the retropharyngeal area, but it is rare for these tumors to arise from the bony, neural, or meningeal components of the cervical spine. (8) To the best of our knowledge, no other case of a fibro-osseous lesion in the retropharyngeal region has been reported in the literature.

Histologic differentiation of fibrous dysplasia and ossifying fibroma is controversial. The stroma of fibrous dysplasia is more collagenous, less vascular, and less cellular than that of ossifying fibroma; the stroma of ossifying fibroma is made up of cellular connective tissue with varying degrees of both osteoblastic and osteoclastic activity. (5) Nevertheless, the biologic behavior of all fibro-osseous lesions is similar, and simple excision generally leads to complete cure, except in the case of aggressive cemento-ossifying fibromas. (5,6)

This case was unusual in that the lesion was acentric and located on the anterior surface of the cervical vertebrae. The patient's globus sensation and dysphagia were attributable to the fact that the mass had protruded through the posterior pharyngeal wall. Imaging studies revealed that although the lesion did not involve neural and vascular structures, it was close enough to them to warrant Doppler ultrasound guidance to lessen the risk of damage to these nearby structures.

References

(1.) Kutluhan A, Kiroglu AF, Yurttas V, et al. Monostotic fibrous dysplasia originating from ethmoid bone: Treatment with endoscopic approach. Ann Otol Rhinol Laryngol 2004; 113:139-41.

(2.) Selesnick SH, Desloge RB, Bullough PG. Protuberant fibro-osseous lesions of the temporal bone: Aunique clinicopathologic diagnosis. Am J Otol 1999;20:394-6.

(3.) Joseph E, Kachhara R, Bhattacharya RN, et al. Fibrous dysplasia of the orbit in an infant. Pediatr Neurosurg 2000;32:205-8.

(4.) Falcioni M, De Donato G. Fibrous dysplasia of the temporal bone. Am J Otol 2000;21:887-8.

(5.) Williams HK, Mangham C, Speight PM. Juvenile ossifying fibroma. An analysis of eight cases and a comparison with other fibro-osseous lesions. J Oral Pathol Med 2000;29:13-18.

(6.) Zupi A, Ruggiero AM, Insabato L, et al. Aggressive cemento-ossifying fibroma of the jaws. Oral Oncol 2000;36:129-33.

(7.) Ramirez-Camacho R, Vicente J, Garcia Berrocal JR, Ramon y Cajal S. Fibro-osseous lesions of the external auditory canal. Laryngoscope 1999;109:488-91.

(8.) Hockstein NG, Anderson TA, Moonis G, et al. Retropharyngeal lipoma causing obstructive sleep apnea: Case report including five-year follow-up. Laryngoscope 2002;112:1603-5.

Muharrem Gerceker, MD; Ozan Bagis Ozgursoy, MD; Atilla Erdem, MD; Cemil Ekinci, MD

From the Department of Otorhinolaryngology--Head and Neck Surgery (Prof. Gerceker and Dr. Ozgursoy), the Department of Neurosurgery (Prof. Erdem), and the Department of Pathology (Prof. Ekinci), School of Medicine, University of Ankara, Ankara, Turkey.

Reprint requests: Ozan Bagis Ozgursoy, MD, Ankara Universitesi Ibni Sina Hastanesi, Kulak Burun Bogaz AD, 06100, Ankara, Turkey. Phone: [phone]; fax: [phone]; e-mail address: [e-mail]

Originally presented at the Uludag ENT Days international meeting; March 4-7, 2004; Bursa, Turkey.