Cyst is a fluid accumulated in a cavity lined by epithelium. Cyst over the hard palate is very infrequent. Cyst is commonly seen along nasoalveolar duct or midline palatal cyst which are congenital. Only few cases of palatine cysts have been reported in literature. We present here a case of 21 years old male with a cystic lesion over the hard palate since 2 years.
Palatine cysts are rare, non-odontogenic fissural cysts of the hard palate. These cysts occur in the midline of the hard palate, behind the incisive canal. These cysts are usually asymptomatic; however they can result in swelling, pain and discharge. The radiological imaging can reveal a round, oval or heart shaped well demarcated image which can be confounding with inflammatory lesions. Being defined to have collection of fluid within a cavity lined by epithelium, a variety of cysts is described. NPDCs are the most common nonodontogenic cysts of the mouth, representing upto 1% of all maxillary cysts [
A 21 years old male presents with a swelling over the hard palate since 2 years and was associated with pain over the swelling (
X-ray reveals a cystic lesion just behind the right upper lateral incisor (
Cysts in the midline of the palate & nasoalveolar or nasopalatine cysts are very uncommon [2,4-8]. The cysts in
this region are usually an extension of cysts from adjacent regions, which involve or cross the midline. The cysts which arise from the midline and expand from there include median palatal cyst, nasopalatine or nasoalveolar cyst and nasopalatal duct cyst [
The nasopalatine duct cyst is a developmental cyst derived from proliferation of embryonic epithelial remnants of the nasopalatine duct. It may occur at any age but it is seen most often in fourth to sixth decades of life. The cause of nasopalatine duct cyst is essentially unknown. Trauma, infection, and mucous retention within associated salivary gland ducts have all been suggested as possible pathogenetic factors; however, most believe that spontaneous cystic degeneration of residual ductal epithelium is the most likely etiology. These are usually central or unilateral with no prevalence of side occurrence. Radiographically, some lesions may appear heartshaped, either because they become notched by the nasal septum during their expansion or because the nasal spine is superimposed on the radiolucent area.
A thorough differential diagnosis must be established in order to avoid unnecessary treatments such as endodontic procedures in vital permanent upper central incisors [2,3]. A correct tentative diagnosis should be based on positive vitality testing and negative percussion findings of the permanent upper central incisors, provided these teeth do not have pulp or periodontal problems [
The differential diagnosis may include an enlarged nasopalatine duct (less than 6 mm in diameter), central giant cell granuloma, a radicular cyst associated to the upper central incisors, follicular cyst associated with mesiodens, primordial cyst, nasoalveolar cyst, osteitis with palatal fistulization, and bucconasal and/or buccosinusal communication [
Median alveolar or midline anterior cyst which is usually found in incisive foramen region is a controversial fissural cyst [
However few cases of median palatine cysts have been reported which may accidentally be found to be present on routine radiographic examination. Approximately about 20 - 30 cases have been reported in last 40 years [
The histopathologic examination of the cystic lining revealed fibrous wall lined by thin stratified squamous epithelium and partly by pseudo stratified columnar epithelium. A few nerve bundles and blood vessels were seen in cyst. These histological features, in conjunction with the site of lesion, suggested palatine cyst, which is regarded as a rare entity [1,6].
The present case is of particular clinical interest as Palatine cysts are rare and it is important that clinician should be aware of the features of this cyst as nearly 40% of the cases are totally asymptomatic and found only during routine clinical examination. Due to extent of the lesion, surgical enucleation was the choice of treatment. Our case demonstrated typical clinical, radiographical and histopathological features of palatine cyst.