Schneiderian papilloma of the nasopharynx. (Original Article).

Abstract

We report a rare case of a schneiderian papilloma of the nasopharynx. Because this tumor is locally invasive, has a tendency to recur, and can undergo malignant transformation, it should be completely excised. It is possible to completely remove such a tumor in a minimally invasive way by using a combination of transnasal and transoral approaches and high-resolution angled endoscopes and other suitably designed instruments.

Introduction

A schneiderian papilloma is a rare, benign neoplasm that is locally invasive, exhibits a tendency to recur, and has malignant potential. It is an interesting lesion that has been the subject of clinicopathologic and therapeutic controversy. The papilloma is derived from the schneiderian membrane, which is the ectodermally derived mucosa that lines the nasal cavity and paranasal sinuses. Because the extent of this epithelium defines the area in which these lesions are found, the appearance of a schneiderian papilloma as a primary tumor outside the sinonasal area is rare.

In this article, we describe our successful management of a case of schneiderian papilloma that arose from the nasopharynx, and we review the limited amount of literature that is available on the subject.

Case report

A 68-year-old Indian man was referred to us by his general practitioner for evaluation of a mass that extended from the nasopharynx to the left oropharynx. The patient was a chronic smoker, and he had a history of allergy to penicillin. Examination revealed the presence of a polypoid mass arising from the left postnasal space in the region of the eustachian tube cushion. An initial punch biopsy of the mass under local anesthesia via the oropharynx identified a squamous metaplasia with mild to moderate dysplasia.

The entire lesion was completely excised under general anesthesia transnasally and transorally with rigid nasoendoscopic guidance. A 4-mm rigid nasoendoscope (0[degrees] and 30[degrees]) was used to view the lesion in the nasopharynx (figure 1). A decongestant was applied to the lesion. A sickle scalpel and endoscopic sinus surgical scissors were used transnasally to excise the upper half of the lesion, leaving at least 0.5 mm of clear margin. Via the oropharynx, the soft palate was superiorly retracted, which allowed the lower half of the lesion to be exposed. The lower half was then similarly excised with a scalpel.

Histologic analysis of the lesion confirmed that it was a schneiderian papilloma (figure 2). The patient recovered without complications, and after more than 2 years of follow-up, he is well and manifests no evidence of recurrence.

Discussion

According to Sulica et al, the ectopic appearance of a schneiderian papilloma outside the sinonasal tract has been reported in cervical lymph nodes, the pharynx, the middle ear, and the mastoid. (1) Knowledge of the embryology of the upper aerodigestive tract helps the surgeon understand the nature of this disease in ectopic sites.

The nasal placodes develop as early as the third week of gestation. They subsequently invaginate centrally to become the nasal pits by the fifth week. The ectodermally derived epithelium that lines these ingrowths forms the schneiderian membrane. The fundus of these pits eventually meets the rostral end of the developing endodermlined pharynx. The resulting bucconasal membrane, consisting of a layer each of ectoderm and endoderm, separates the two compartments. This structure eventually breaks down, allowing for communication between the two cavities. By 10 weeks, the growth of the lateral palatal shelves separates the nasal and oral compartments, and the developing septum divides the nasal cavity into right and left halves. The choanae represent the watershed area between ectodermally and endodermally derived epithelia. This process occasionally results in the migration or incorporation of schneiderian membrane into areas where it is not normally found. Subsequent inflammation of this tissue--either by envir onmental, viral, or other agents-- can result in the development of a papilloma. (1)

In a previous report of nasopharyngeal schneiderian papilloma, Astor et al described patients who had similar lesions in the nasal cavity. (2) Our patient had a solitary nasopharyngeal schneiderian papilloma that did not involve the nasal cavity. It is interesting that this tumor was firm, had a smooth surface, and was not associated with any significant contact bleeding. These findings are in contrast with the typical characteristics of schneiderian papillomas in the sinonasal tract, which tend to be friable and papillomatous and bleed easily when touched. (2,3) The case of our patient also illustrates the limitations of surface punch biopsies, which do not always yield a true histologic diagnosis.

Because schneiderian tumors are locally invasive, have a tendency to recur, and can undergo malignant transformation, they should be completely excised. Traditionally, the intranasal approach had generally been considered an unsafe method of removing a schneiderian papilloma from the nose. Because this method is limited by inadequate visualization and access, it has resulted in recurrence rates as high as 60%. (4) More radical operations-- such as lateral rhinotomy, (5) midfacial degloving, (6) and Denker's approach (7)--have been used to provide better access. However, these open approaches are associated with increased morbidity.

In recent years, with the advent of endoscopic sinus surgery, high-resolution angled endoscopes and suitably designed instruments have provided excellent visualization and access to the sinonasal regions. Originally used for treating sinusitis and nasal polyposis, these transnasal endoscopic approaches have recently been used for the removal of schneiderian papillomas from the sinonasal region with good results. (8)

There are no reports of endoscopic techniques being used to treat schneiderian papillomas of the nasopharynx. Because nasopharyngeal schneiderian papillomas are rare, published recommendations on how they should be managed are scarce. As with sinonasal schneiderian papillomas, the goal of treatment should be complete removal with minimal morbidity. (5) Wolff et al described a case of nasopharyngeal schneiderian papilloma that was successfully removed via a midline soft palate incision. (9) Minimally invasive excision of lesions in the nasopharynx via intranasal and intraoral routes in the past have been hampered by poor visualization, access, and instrumentation. These limitations can be overcome with the use of high-resolution straight and angled endoscopes and endoscopic sinus surgery instruments, as illustrated by our case. In our patient, we had no difficulty in completely removing the schneiderian papilloma from the nasopharynx with straight and angled endoscopic sinus instruments via a combined transnasal and transoral approach. The use of the instruments provided excellent visualization and control.

Sanderson and Knegt reported that recurrence of schneiderian papillomas almost always occurs within 2 years of the original operation, often within months. (7) Our patient has been observed for more than 2 years and has shown no evidence of recurrence.

References

(1.) Sulica RL, Wenig BM, Debo RF, Sessions RB. Schneiderian papillomas of the pharynx. Ann Otol Rhinol Laryngol 1999; 108:392-7.

(2.) Astor FC, Donegan JO, Gluckman JL. Unusual anatomic presentations of inverting papilloma. Head Neck Surg 1985;7:243-5.

(3.) Vrabec DP. The inverted Schneiderian papilloma: A 25-year study. Laryngoscope 1994;104:582-605.

(4.) Murray JA. The nose: Benign tumours and granulomas. In: Maran AG, ed. Logan Turner's Diseases of the Nose, Throat and Ear. 10th ed. Oxford: Butterworth Heinman, 1988:56-63.

(5.) Phillips PP, Gustafson RO, Facer GW. The clinical behavior of inverting papilloma of the nose and paranasal sinuses: Report of 112 cases and review of the literature. Laryngoscope 1990;100:463-9.

(6.) Buchwald C, Franzmann MB, Tos M. Sinonasal papillomas: A report of 82 cases in Copenhagen County, including a longitudinal epidemiological and clinical study. Laryngoscope 1995; 105:72-9.

(7.) Sanderson RJ, Knegt P. Management of inverted papilloma via Denker's approach. Clin Otolaryngol 1999;24:69-71.

(8.) Chee LW, Sethi DS. The endoscopic management of sinonasal. inverted papillomas. Clin Otolaryngol 1999;24:61-6.

(9.) Wolff AP, Ossoff RH, Clemis JD. Four unusual neoplasms of the nasopharynx. Otolaryngol Head Neck Surg 1980;88:753-9.

From the Department of Otolaryngology (Dr. Low, Dr. Toh, and Dr. Lim) and the Department of Pathology (Dr. Ramesh), Singapore General Hospital.

Reprint requests: Dr. Wong-Kein Low, Department of Otolaryngology, Singapore General Hospital, Singapore 169608, Republic of Singapore. Phone: [phone]; fax: [phone]; e-mail: [e-mail]