|Year : 2016 | Volume
| Issue : 2 | Page : 223-226
Lesion on palate: A diagnostic dilemma
Swati N Chavan1, Jitendra K Rathod2
1 Department of Oral Medicine and Radiology, Chatrapati Shahu Maharaj Shikshan Sanstha Dental College, Kanchanwadi, Aurangabad, Maharashtra, India
2 Department of ENT, Mahatma Gandhi Mission College and Hospital, Aurangabad, Maharashtra, India
|Date of Submission||05-Aug-2015|
|Date of Acceptance||21-Nov-2016|
|Date of Web Publication||02-Dec-2016|
Dr. Swati N Chavan
C/O Dr. Jitendra K. Rathod, Flat No. 01, Plot No. 53, Wadkar Residency, Near Morya Mangak Karyalaya, Shivaji Nagar, Aurangabad, Maharashtra
Source of Support: None, Conflict of Interest: None
| Abstract|| |
A non-ulcerated mucosal swelling on hard palate presents a challenge to the clinicians. Thorough clinical, radiographic and histopathological evaluations are mandatory. Here, we report a case of mucosal swelling on the hard palate of a 52-year-old male patient. On clinical examination, there was a dome-shaped, firm swelling seen on the left side of the posterior hard palate. On computed tomography (CT), the lesion appeared as round homogenously enhancing mass/lesion epicentered over the mucosa overlying the posterior part of the half of hard palate extending into the adjacent soft palate. When biopsy was performed, the histopathology report was suggestive of pleomorphic adenoma of palate. Pleomorphic adenoma is the most common tumor of the salivary glands; it accounts for approximately 60% of all salivary gland tumors. CT or magnetic resonance imaging should be considered when assessing for the presence of bony erosion or soft tissue and nerve involvement. Ultimately, complete surgical excision provides the definitive diagnosis and treatment for this noteworthy salivary gland neoplasm. Pleomorphic adenoma is commonly encountered in the parotid gland and other major salivary glands. At times they can also develop in minor salivary glands of the palate.
Keywords: Computed tomography, magnetic resonance imaging, pleomorphic adenoma
|How to cite this article:|
Chavan SN, Rathod JK. Lesion on palate: A diagnostic dilemma. J Indian Acad Oral Med Radiol 2016;28:223-6
| Introduction|| |
Pleomorphic adenoma is a mixed benign tumor composed of epithelial and myoepithelial cells arranged with various morphological patterns demarcated from the surrounding tissues by fibrous capsule.  Pleomorphic adenoma is the most common tumor of the salivary glands, accounting for approximately 60% of all salivary gland tumors. The majority of these tumors are found in the parotid glands, with less than 10% in the submandibular, sublingual and minor salivary glands.  Parotid gland is most commonly affected among the major group, and palate is the most common site of minor salivary glands that are affected. Other intraoral sites for pleomorphic adenoma are the lips, buccal mucosa, floor of the mouth, tongue, tonsil pharynx, and retromolar area.  Although pleomorphic adenoma commonly occurs in major salivary glands, here we report a rare case of pleomorphic adenoma that occurred in minor salivary glands of the palate.
| Case Report|| |
A 52-year-old male patient reported to the Department of Oral Medicine and Radiology with the chief complaint of a painless swelling over the left palatal region since 6 months. On general examination, all the vital signs were within normal range with no significant history of medical illness. There was a history of extraction in the upper left back region of the jaw 1 year back. The patient gave a history of tobacco chewing since 20 years. On further asking, the patient revealed that the swelling was initially small in size that gradually increased to the present size. Extraorally, there was no facial asymmetry and no accompanying lymphadenopathy. Intraoral examination revealed a single, well-defined, dome-shaped swelling on left side of the posterior hard palate which measured approximately 2 × 3 cm. Anteroposteriorly, the swelling extended from the distal aspect of upper left first molar to the junction of hard and soft palate. Mediolaterally, it extended from the midpalatal area to the lingual aspects of maxillary molar teeth on the left side. The surface texture was smooth. The overlying mucosa was slightly inflamed. Draining sinus or fistula was not evident. The surrounding mucosa was normal. On palpation, all the inspectory findings were confirmed. The swelling was single, nontender, firm in consistency, attached to the underlying mucosa but not to the overlying mucosa. The edges of the swelling were smooth. The swelling was compressible, but fluctuation, pulsation and reducibility were absent. Hard tissue examination revealed generalized attrition, stains and calculus with missing maxillary left first molar [Figure 1]. A clinical diagnosis of minor salivary gland tumor was given and required investigations were performed.
|Figure 1: A single, dome-shaped, circumscribed swelling present on left side of the posterior hard palate|
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An intraoral periapical radiograph was taken of the left maxillary posterior region, which revealed no abnormality. Fine needle aspiration was nonproductive. The prone coronal computed tomography (CT) scan of paranasal sinus was obtained using multidetector CT scanner. A 2.1 cm (cranial-caudal) ×2.0 cm (anteroposterior) ×2.0 cm (transverse) round homogenously enhancing mass was noted at the epicentre over the mucosa overlying the posterior half of the hard palate extending into the adjacent soft palate. There was no calcification of fatty tissue component and no obvious bone erosion was seen [Figure 2]a and b.
|Figure 2: (a and b) The prone computed tomography (CT) scan of paranasal sinus (PNS) was obtained using multidetector CT showing the PNS in coronal, axial, and sagittal section. There was 2.1 cm (cranial- caudal) ×2.0 cm (anteroposterior) ×2.0 cm (transverse) round homogenously enhancing mass/lesion noted at the epicentre over the mucosa overlying the posterior part of half of hard palate extending into the adjacent soft palate. There was no calcification of fatty tissue component, and no obvious bone erosion was noted|
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Excisional biopsy was performed under local anaesthesia. A single well-encapsulated nodular mass measuring 2.2 × 1.7 × 1.2 cm specimen was sent to the pathology laboratory [Figure 3]. Histopathological examination showed well-encapsulated tumor composed of ducts lined by epithelial and myoepithelial cells in the sheets, ducts and clusters set in a chodromyxoid and hyalinized stroma. Squamous metaplasia and squamous cysts were seen. The tumor had focally pushing margins. On the basis of this histological examination, the diagnosis of pleomorphic adenoma was made [Figure 4].
|Figure 3: Excisional biopsy shows a single well-encapsulated nodular mass measuring 2.2 × 1.7 × 1.2 cm|
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|Figure 4: High power view showing many ducts, and myoepithelial cells are surrounded by a hyalinized, eosinophilic background alteration|
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| Discussion|| |
Pleomorphic adenoma is the most common tumor (50%) of the large salivary glands and affects mostly the parotid gland, and less frequently (10%) the accessory salivary glands.  Palate is considered as the most common intraoral site (60%), followed by the upper lip (20%) and the buccal mucosa (10%).  A variety of names have been suggested for pleomorphic adenoma such as mixed tumor, enclavoma, branchioma, endothelioma, and enchondroma. It contains both epithelial as well as myoepithelial elements, and is hence considered as a mixed tumor of salivary gland. 
Pleomorphic adenoma appears as a slowly growing, painless, firm mass that rarely ulcerated the overlying skin and mucosa. The tumor can occur at any age, however, it is most common in young and middle-aged adults between the ages of 30-60 with a slight female predilections. , The patient presented with a history of painless swelling for 6 months in posterior left half of the hard palate, which had gradually increased in size. Differential diagnosis on the basis of clinical presentation and advance imaging, such as CT scan included salivary gland tumors, odontogenic and nonodontogenic cyst, abscess, maxillary sinus carcinoma, adenoid cystic carcinoma, and squamous cell carcinoma.
Periapical abscess can be ruled out by clinical examination since the source of abscess, which is typically a nonvital tooth in vicinity or a localized periodontal defect, was not found. , Both odontogenic and nonodontogenic cysts can be ruled out at the time of exploration into the mass because it did not demonstrate cystic nature.  Lymphoma constitutes a diverse and complex group of malignancies of lymphoid histogenesis. The most frequent location of extranodal lymphoma in the head and neck is the palate. Lymphomas usually appear as a nontender diffuse mass and are rarely ulcerated. Many salivary gland lymphocytic infiltrates of the palate are actually non-Hodgkin's B-cell lymphomas of the mucosa-associated lymphoid tissue, and hence it should be considered in the differential diagnosis.  Adenoid cystic carcinoma is an uncommon, slow growing malignant salivary gland tumor. Intraorally, 50% of adenoid cystic carcinomas occur on the palate. Adenoid cystic carcinoma accounts for 8.3% of all palatal salivary gland tumors and 17.7% of malignant palatal salivary gland tumors. The most common initial symptom of adenocystic carcinoma is the presence of a mass. Less common as first symptoms are pain and tenderness. , Many of the features were conforming with the presented case and should be considered in the differential diagnosis. Carcinoma of the maxillary sinus usually remains asymptomatic for a long period of time. Eventually, the tumor grows to fill the sinus and the diagnosis is made because the lesion has pronounced a bulge on the palatal/alveolar ridge area. This tumor is associated with elderly patient. However, no abnormality is detected on the coronal section of CT, except polypoid mucosal thickening of both halves of the maxillary sinus and slight deviation of nasal septum to the right side. Carcinoma of the nose and paranasal sinuses is a very rare entity. , Palatal tissues contain components of soft tissue. Therefore, soft tissue tumors such as fibroma, lipoma, neurofibroma, neurilemmoma should also be considered in the differential diagnoses for this case, however, thorough clinical examination can rule out these lesions. 
Although the occurrence of pleomorphic adenoma on palate is rare, it should be considered in the differential diagnosis of mucosal swelling of hard palate. Histopathologically, pleomorphic adenoma is an epithelial tumor of complex morphology, possessing epithelial and myoepithelial elements arranged in a variety of patterns and embedded in a mucopolysaccharide stroma. Formation of the capsule is as a result of fibrosis of surrounding salivary parenchyma, which is compressed by the tumor and is referred to as false capsule. 
CT scanning is the best for bony involvement of the palatal lesions, and magnetic resonance imaging (MRI) is better to display soft tissue invasion and perineural spread. These help in determining the extent of disease, local spread and also help to some extent in determining the type of tumors. Presence of intact fat plane helps in distinguishing benign tumors from malignant one. CT or MRI should be considered when assessing the presence of bony erosion or soft tissue and nerve involvement. Ultimately, complete surgical excision provides the definitive diagnosis and treatment for this noteworthy salivary gland neoplasm.  Surgical excision is the best treatment plan for pleomorphic adenoma. Pleomorphic adenoma is encapsulated, and an incomplete excision can leave behind residual tumor cells, resulting in recurrence because of its high rate of implantability.
| Conclusion|| |
This case represents an exceptional example of pleomorphic adenoma of the palate. Successful treatment begins with an appropriate referral and a biopsy-proven diagnosis. CT aids in evaluating the extent of the lesion and in guiding the surgical strategy. A long-term follow-up is warranted because of the risk of recurrence even several years after the initial excision.
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| References|| |
Shafer, Hine, Levy. Benign tumors of the salivary glands. In: Rajendran R, editor. Shafer's textbook of Oral Pathology, 6 th
ed. Noida. Elsevier; 2009. p. 219-24.
Greenberg MS, Glick M, Ship JA. Salivary gland disease. In: Fox PC, Ship JA, editors. Burket's Oral Medicine, 11 th
ed. Hamilton: BC Decker Inc; 2008. p. 217.
Sharma Y, Maria A, Chhabria A. Pleomorphic adenoma of the palate. Natl J Maxillofac Surg 2011;2:169-71.
Neville BW, Damm DD, Allen CM, Bouquot JE. Salivary gland tumors. Oral and Maxillofacial Pathology. 2 nd
ed. Pennsylvania: Saunders; 2004. p. 410-4.
Estrela C, Guedes OA, Silva JA, Leles CR, Estrela CR, Pecora JD. Diagnostic and clinical factors associated with pulpal and periapical pain. Braz Dent J 2011;22:306-11.
Grossman LI, Oliet S, Rio CE. Diseases of the periradicular tissues. Endodontics Practice. 11 th
ed. Bombay: Varghese publishing house; 1988. p. 85-96.
Dhanuthai K, Sappayatosok K, Kongin K. Pleomorphic adenoma of the palate in a child: A case report. Med Oral Pathol Oral Cir Bucal 2009;14:E73-5.
Manveen JK, Subramanyam RV, Harshminder G, Madhu S, Narula R. Primary B-cell MALT lymphoma of the palate: A case report and distinction from benign lymphoid hyperplasia seudolymphoma). J Oral Maxillofac Pathol 2012;16:97-102.
Chundru NSV, Amudala R, Thankappan P, Nagaraju D. Adenoid cystic carcinoma of palate: A case report and review of literature. Dent Res J 2013:10:274-8.
Touloukia R J salivary gland diseases in infants and children. In: Rankow R M, Polayes LM (Eds). Diseases if salivary glands. Philadelphia: W B Saunders; 1976. p. 284-303.
Terada T. Primary small cell carcinoma of the maxillary sinus: A case report with immunohistochemical and molecular genetic study involving KIT and PDGFRA. Int J Clin Exp Pathol 2012;5:264-9.
Ishida M, Okabe H. Basaloid sqamous cell carcinoma of the maxillary sinus: Report of two cases in association with cathepsin K expression. Oncol Lett 2013;5:1755-9.
Debnath SC, Saikia AK, Debnath A. Pleomorphic Adenoma of the Palate. J Maxillofac Oral Surg 2010;9:420-3.
Lowry TR, Hiechel DJ. Pleomorphic adenoma of the palate. Otolaryngol Head neck Surg 2004;131:793.
[Figure 1], [Figure 2], [Figure 3], [Figure 4]