Inferior turbinate schwannoma: report of a case.

Abstract

Schwannomas of the nasal cavity are extremely rare. We evaluated a 42-year-old woman who presented with a 4-year history of slowly progressive nasal obstruction. The cause of the obstruction was identified as a schwannoma in the left inferior turbinate. The tumor was completely excised, and no sign of recurrence was evident at the 1-year follow-up. To the best of our knowledge, this is only the third case of a schwannoma originating in the inferior nasal turbinate that has been reported in the English-language literature. We review the clinical and pathologic features of this case.

Introduction

Schwannomas of the head and neck are common, but involvement of the nasal cavity and paranasal sinuses is rare. (1-16) A case of intranasal schwannoma originating in the inferior turbinate was reported in 1976, (1) and a second case was reported in 2001. (2) In this article, we describe what to the best of our knowledge is only the third case of a schwannoma originating in the inferior turbinate that has been reported in the English-language literature.

Case report

A 42-year-old woman was admitted to our otolaryngology department complaining of a progressive nasal obstruction of 4 years' duration. Her medical history was unremarkable. Physical examination, including endoscopy of the nose and nasopharynx, revealed that the nasal cavity was obstructed by a massive hypertrophy of the left inferior turbinate. No other abnormalities were detected. Computed tomography (CT) showed that the hypertrophy had originated in the left inferior concha and extended into the left side of the nasopharynx (figure 1, A). With the patient under general anesthesia, an endoscopic approach was used to excise the polypoid tissue.

[FIGURE 1 OMITTED]

Histology showed that fragments of respiratory mucosa and soft tissue had been infiltrated by a demarcated spindle cell tumor with alternating areas of Antoni type A and Antoni type B patterns (figure 2). No mitotic figures were found, and there was no evidence of necrosis or mucosal invasion. Staining with S-100 protein was intensely positive. Actin, desmin, and keratin stains were negative.

[FIGURE 2 OMITTED]

The patient's postoperative course was uneventful. Follow-up CT 6 months after surgery revealed a patent airway and no evidence of a residual or recurrent mass (figure 1, B).

Discussion

Almost all schwannomas are solitary encapsulated tumors that do not entrap the nerve axons but rather push them aside. Schwannomas are not associated with neurofibromatosis, and malignant degeneration is rare. (3)

Histologically, schwannomas are made up of spindle cells arranged in two distinct patterns. In the Antoni type A pattern, the cells are embedded in tissue and aligned in a palisade fashion, with the nuclei lying side by side in one strip and the cytoplasm in an adjacent strip (Verocay bodies). (4,5) In the Antoni type B pattern, there is no specific arrangement of cells. Throughout the tumor, there are changes represented by areas of hyalinosis, cystic degeneration, and lipidization. Microangiomatous clusters of vessels are frequently seen. (1,5,6)

In 1976, Kaufman and Conrad described an intranasal schwannoma that presented as a nasal polyp originating in the posteroinferior aspect of the inferior turbinate in a 55-year-old man. (1) The inferior turbinate was excised, and the patient was thereafter asymptomatic. The other nasal schwannoma, reported by Yang et al in 2001, originated in the left middle turbinate in a 39-year-old man who had presented with nasal obstruction and purulent rhinorrhea. (2) Pathologic examination of the excised schwannoma revealed a nonencapsulated tumor with a palisade-like cellular arrangement and high cellular density. The clinical presentation of our patient was similar to those in both of these previously reported cases. After complete endoscopic removal of the tumor, our patient remained asymptomatic at the 1-year follow-up.

Typical features of schwannomas of the nasal cavity are nasal obstruction and epistaxis. These tumors are considered to be radioresistant, so the treatment of choice is resection. (6) Their clinical course is benign, but if they are not excised completely, they may recur. Intracranial extension of nasal schwannomas has been described, as has malignant degeneration. (6)

Because nasal schwannomas are so rare, we suspect that some are actually misdiagnosed as nasal polyps. The existence of nasal schwannomas should be kept in mind when dealing with patients who present with what appears to be a solitary nasal polyp.

References

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(13.) Schwartz TH, Bruce JN. Extended frontal approach with bilateral orbitofrontoethmoidal osteotomies for removal of a giant extracranial schwannoma in the nasopharynx, sphenoid sinus, and parapharyngeal space. Surg Neurol 2001;55:270-4.

(14.) Takara CK, Granato L, Taciro E, et al. Nasal septum schwannomas--Case report and review of the literature. Brazilian J Otorhinolaryngol 2001;67:35-42.

(15.) Wada A, Matsuda H, Matsuoka K, et al. A case of schwannoma on the nasal septum. Auris Nasus Larynx 2001;28:173-5.

(16.) Alessandrini M, Nucci R, Giacomini PG, et al. A case of solitary nasal schwannoma. An Otorrinolaringol lbero Am 2001;28: 201-8.

Riad Khnifies, MD; Milo Fradis, MD; Alexander Brodsky, MD; Jacob Bajar, MD; Michal Luntz, MD

From the Department of Otolaryngology--Head and Neck Surgery (Dr. Khnifies, Dr. Fradis, Dr. Brodsky, and Dr. Luntz) and the Department of Pathology (Dr. Bajar), B'nai Zion Medical Center, Faculty of Medicine, Technion-Israel School of Technology, Haifa, Israel.

Reprint requests: Michal Luntz, MD, Department of Otolaryngology--Head and Neck Surgery, B'nai Zion Medical Center, P.O. Box 4940, 31048 Haifa, Israel. Phone: [phone]; fax: [phone]; e-mail: [e-mail]