Mucoepidermoid carcinoma (MEC), one of the most common salivary gland malignancies, is rare in children. MEC mainly occurs in the parotid gland, along with minor glands being the second common site, particularly in palate. Clinical, histological, and radiological findings of palatal MEC in a 12-year-old girl are presented with three-year follow-up. Pathologic lesions must be considered in differential diagnoses of intraoral asymptomatic lesions, and their detailed inspection should be taken into consideration.
Mucoepidermoid carcinoma (MEC) is one of the most common salivary gland malignancies. As its name implies, MEC is composed of a mixture of cells, including mucus-producing, epidermoid or squamous, and intermediate types [
Few series or case reports describing salivary gland tumors in the pediatric population have been published [
A 12-year-old girl patient visited the Department of Pediatric Dentistry, Ataturk University, Erzurum, Turkey, complaining of the pain in maxillar left central incisor (no. 11) and mandibular left lateral incisor (no. 22). She had a history of untreated Ellis II trauma and grade two mobility in these teeth for two years. Also, clinical examination revealed enlargement of the soft tissue in left posterior hard palate, with 8 mm diameter (Figure
(a) Preoperative intraoral image of a mucoepidermoid carcinoma of the left posterior hard palate with 8 mm diameter and fistula opening (black arrow). (b) Postoperative (3 years) image of a reconstructed palate.
Dental volumetric tomography images of MEC (black arrows); (a) axial, (b) sagittal, (c) coronal, and (d) 3D image.
Histopathology showing mucous secreting cells and intermediate cells.
Epithelial salivary gland neoplasms are rare both in adults and children, accounting for less than 3% of all head and neck tumors. 5% of these tumors occur in patients younger than 18 years old with girls mostly affected, while its occurrence in newborns is exceedingly rare [
As a typical intraoral presentation this malignancy has a painless and persistent enlargement, which lasts for about a year. Paresthesia, pain, and difficulty with swallowing are noted frequently when major salivary glands and tongue are involved. Intraoral lesions are observable as a localized fluctuant nodule with a bluish or reddish-purple, smooth, mucosal surface. Like in our study, mucus may be discharged from the tumor through a small sinus tract [
Radiographically low-grade MECs are similar to benign mixed tumors. They demonstrate smooth margins and are characterized by cystic components containing mucin. On the other hand high-grade MECs have poorly defined margins, local infiltrations, and solid appearances [
The clinical and radiographic differential diagnosis of a palatal mass includes reactive and neoplastic lesions. In children, the most common of these entities is the palatal space abscess derived from pulpal necrosis. They are differentiated by tooth mobility, diffuse, erythematous swelling of sudden onset, suppuration, fluctuation in lesion size, and radiographic evidence of inflammatory pulpal disease. Mucocele is a frequently seen fluctuant reactive lesion of salivary glands, with transparent blue swelling including mucin. Deep mucoceles, often surrounded by a fibrous tissue wall, do not fluctuate, and if located at sites other than the lower lip cannot clinically and reliably be differentiated from salivary gland tumors. Our case was not similar to a mucocele because mucin discharged from a sinus opening. Palatal region vascular malformations like hemangiomas are differentiated by clinical examination and imaging. Neurofibroma and schwannoma are occasionally encountered as compressible or firm asymptomatic nodules and pink in color unless they are secondarily traumatized [
The tumor is dissected down to the periosteum to obtain adequate tumor-free margins [
Radiation therapy should be used judiciously in pediatric patients with high-grade histology, positive margins, and lymph node involvement, due to its long-term consequences as facial deformity, trismus, xerostomia, osteoradionecrosis, and risk of secondary malignancy. Chemotherapy was not used as an adjuvant therapy in our patient and does not currently have a role in the standard treatment of MEC patients [
There is a potential risk of the development of a mucoepidermoid carcinoma in parotid and minor salivary glands of children who have received chemotherapy and cranial irradiation [
In this case it is noteworthy that swellings in the palatal area which could resemble a dental abscess can cause unnecessary treatments, waste of time, and delay in diagnosis. Although mucoepidermoid carcinoma and other tumors in this region are exceedingly rare, patients with these kinds of swellings must be considered cautiously, and multidisciplinary approach can lead to successful treatment.