* Address correspondence to this author at the Resident of Department of Oral Surgery and Implantology, University of Milan, IRCSS, Via della Commenda 10 Milano, 20140 Italy; Tel: +390255032621; E-mail: ti.oohay@ocramorca
Received 2009 Jun 15; Revised 2009 Oct 9; Accepted 2009 Nov 2. Copyright © Cicciù et al.; Licensee Bentham Open.This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
The nasopalatine duct cyst (NPDC) is the most common of the non-odontogenic cyst of the jaws. This cysts are usually central or unilateral with no prevalence of side occurrence. The NPDC is the most frequent developmental, nonodontogenic cyst of the jaws. This cyst originates from epithelial remnants from the nasopalatine duct. The cells could be activated spontaneously during life, or are eventually stimulated by the irritating action of various agents (infection, etc.). Generally, patients present without clinical signs and symptoms. Therefore, the tentative diagnosis "nasopalatine duct cyst" is often based on a coincidental radiological finding on a routine panoramic view or occlusal radiograph. The definite diagnosis should be based on clinical, radiological and above all histopathologic findings. The therapy of nasopalatine duct cysts consists of an enucleation of the cystic tissue, only in rare cases a marsupialization needs to be performed. This report describes the appearance and treatment of a rare case of bilateral nasopalatine duct cyst.
The nasopalatine duct cyst (NPDC) is an intraosseous developmental cyst of the midline of the anterior palate. This cyst comprises about 11.6% of all jaw cysts in the maxillofacial region1 and is considered the most common non-odontogenic cyst, accounting for approximately 73% of those reported [1]. The majority of cases occur in the third to the sixth decades, and most studies show a significantly higher frequency of nasopalatine duct cysts in men that woman, the ratio being 2.5:1 [2-8]. As far as pathogenesis is concerned, it was previously thought that the NPDCs originated from the trapping of epithelium during fusion of the embryological processes [9]. This concept has been discarded, and currently NPDC is thought to develop from the epithelial remnants of the nasopalatine ducts present within the incisive canals (canals of Stenson) [3, 6, 7]. The NPDC is unique in that it develops in only one location, which is the midline of the anterior maxilla, in close relationship to the nasopalatine canal. The most common symptom is swelling, usually in the anterior region of the midline of palate. Swelling also occurs in the midline on the labial aspect of the alveolar ridge. In a number of cases, the swelling is associated with pain or drainage [6, 7, 10]. Some cysts may also be completely symptomless and be discovered by the dentist during routine radiological examination [10]. In establishing a diagnosis of NPDC it is important to attempt to exclude the possibility of a periapical lesion by testing the pulp vitality of the incisor teeth. Radiologic examination demonstrates a well-demarcated cystic structure that may appear round, ovoid or heart-shaped [11]. Trauma or bacterial infections have been mentioned as possible triggers, but there is very little evidence to support such hypotheses. Although aetiology of this lesion is still uncertain, the NPDC most likely represents a spontaneous cystic degeneration of remnants of the nasopalatine duct [11-13] and some genetic determinants have been suggested [14]. The microscopic features of the epithelial lining of NPDCs are highly variable, depending on the relative proximity of the nasal and oral cavities. It has been averred that cysts lined by respiratory epithelium probably originate from most superior part of the nasopalatine duct, whereas those lined by cuboidal and squamous epithelium usually originate from the lower portion of the duct, close to the oral cavity. However, the majority of cyst lining have a combination of epithelial varieties and it is not really possible to correlate position with histology. Surgical enucleation is the treatment of choice with very low recurrence rate [5, 6, 15]; however, marsupialization is an acceptable alternative in select patients [10]. Although transformation to malignancy is exceedingly rare, a single case of squamous cell carcinoma development in NDPC has been reported [16]. In this article, we describe the first reported case of bilateral nasopalatine duct cyst.
A 35-year-old, black man presented to the Oral and Maxillofacial Surgery Department of the University of Milan, I.C.P. Dental School. The patient’s main complaint was swelling and elevation of the right and left nasolabial regions since 1 month. On palpation, a soft, fluctuant mass was observed which extended from the anterior buccal area up to the floor of the nose. Radiographic examination (orthopantomograph and CT scan) (Figs. 1 1 , 2 2 ) showed two different and separated radiolucent areas in the periapical region of the upper incisors. Vitality test was positive for all anterior teeth.