Solitary fibrous tumor of the maxillary sinus

Ear, Nose & Throat Journal, July, 2007 by Lorraine M. Smith, Ryan F. Osborne

A 43-year-old man presented with an 18-month history of progressive bilateral nasal obstruction, greater on the fight than on the left, and associated clear rhinorrhea and anosmia. He also reported that his right eye had protruded. He denied diplopia, vision changes, facial pain, headaches, and a history of sinusitis.

In addition to the mild right exophthalmos, physical examination revealed fullness over the right maxilla that extended to the temporal area. Inside the nasal cavity, bilateral inferior turbinate hypertrophy and irregular nasal mucosa on the right at the level of middle turbinate were noted. In addition, the medial maxillary sinus wall was bulging into the nasal airway. Nasal endoscopy confirmed the presence of an expansile mass that was obstructing the middle and superior portions of the right nasal vault. Endoscopic examination of the left nasal cavity revealed no masses in the nasopharynx.

Computed tomography (CT) of the sinuses identified a 7.3-cm soft-tissue mass in the right maxillary sinus and erosion of the anterior maxillary sinus wall (figure 1). The erosion extended medially into the right ethmoid sinus and nasal cavity, superiorly into the orbit, and laterally into the right masseteric space and infratemporal fossa.

[FIGURE 1 OMITTED]

The mass was biopsied endoscopically. Pathology results were significant for a mesenchymal spindle-cell tumor (low-grade cytology), with features consistent with a solitary fibrous tumor (figure 2, A). No cytologic atypia, necrosis, or mitotic activity was seen. Immunoreactivity evaluations revealed a diffuse stain for vimentin (figure 2, B) and weakly positive stains for CD34, CD99, Bcl-2, and smooth-muscle actin; stains for epithelial markers, melanoma markers, S-100 protein, and desmin were negative.

The patient underwent a right maxillectomy with orbital preservation via a lateral rhinotomy (figure 3, A). The right orbital floor was reconstructed, and a palatal prosthesis was placed. The long-term cosmetic outcome was excellent (figure 3, B). The final pathology report with the same immunologic stains was consistent with that of the biopsy.

Most benign epithelial tumors of the sinonasal tract are papillomas and adenomas. Even though papillomas are benign, they can be locally invasive; they can extend beyond their site of origin; they can destroy bone; they can recur when not excised completely; and they may be associated with malignant tumors. Solitary fibrous tumors of the sinonasal tract are relatively rare. These spindle-cell tumors were originally described in the pleura and peritoneum. (l) (2) By definition, these tumors are CD34-positive. The most common symptoms in affected patients are nasal obstruction, epistaxis, and later facial and/or nasal pain. The location of the mass is often revealed by nasal endoscopy.

CT and magnetic resonance imaging are useful for tumor mapping because they identify eroded or deformed bony structures and soft-tissue extension. Radiologic evidence of orbital-floor erosion is often confirmed surgically. In cases where there is no evidence of orbital periosteal invasion, the eye may be preserved. (3) Because solitary fibrous tumors tend to recur after local resection, we recommend that the surgeon (1) perform a wide local resection that follows the path of the tumor and (2) pay special attention to preserving or reconstructing facial contour. When recontouring the face after maxillectomy, the senior author (R.EO.) has had good results with hydroxyapatite and replating the zygomatic arch.

[FIGURES 2-3 OMITTED]

References

[1.] Cassarino DS, Auerbach A, Rushing EJ. Widely invasive solitary fibrous tumor of the sphenoid sinus, cavernous sinus, and pituitary fossa. Ann Diagn Pathol 2003;7(3):169-73.

[2.] Dotto JE, Ahrens W, Lesnik DJ, et al. Solitary fibrous tumor of the larynx: A case report and review of the literature. Arch Pathol Lab Med 2006;130(2):213-16.

[3.] Myers E. Neoplasms of the nose and paranasal sinuses. In: Bailey BJ, ed. Head and Neck Surgery-Otolaryngology. Vol. 2. Philadelphia: J.B. Lippincott; 1993:1092-7.

From the Cedars-Sinai Medical Group, Beverly Hills, Calif. (Dr. Smith), and the Osborne Head and Neck Institute, Los Angeles (Dr. Osborne).