|Year : 2017 | Volume
| Issue : 4 | Page : 321-324
Minor Salivary Gland Neoplasms of Palate: Case Series with Differential Diagnosis and Review of Literature
Kamala Rawson1, Basavaraj Kallali2, Arun George3, Admaja K Nair1
1 Department of Oral Medicine and Radiology, Mar Baselios Dental College, Ernakulam, Kerala, India
2 Department of Oral Medicine and Radiology, Hazaribag College of Dental Sciences, Hazaribag, Jharkhand, India
3 Department of Oral and Maxillofacial Surgery, Mar Baselios Dental College, Ernakulam, Kerala, India
|Date of Submission||24-Jun-2017|
|Date of Acceptance||24-Jan-2018|
|Date of Web Publication||15-Feb-2018|
Dr. Kamala Rawson
Department of Oral Medicine and Radiology, Mar Baselios Dental College, Kothamangalam, Kerala
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Minor salivary gland tumors are infrequent, accounting for 10–15% of all salivary neoplasms. The most common intraoral site is palate, accounting for more than 50% of cases followed by lips, cheek mucosa, tongue, and floor of the mouth. Despite their relatively low frequency, minor salivary gland neoplasms represent a heterogeneous group of lesions, with a broad range of histological types and growth patterns imposing a diagnostic dilemma for the clinicians. Here we are reporting four cases of minor salivary gland neoplasms, all presented as palatal swellings of similar characteristics, and a review of literature is done for the same.
Keywords: Minor salivary gland tumor, mucoepidermoid carcinoma, palatal swellings, pleomorphic adenoma
|How to cite this article:|
Rawson K, Kallali B, George A, Nair AK. Minor Salivary Gland Neoplasms of Palate: Case Series with Differential Diagnosis and Review of Literature. J Indian Acad Oral Med Radiol 2017;29:321-4
|How to cite this URL:|
Rawson K, Kallali B, George A, Nair AK. Minor Salivary Gland Neoplasms of Palate: Case Series with Differential Diagnosis and Review of Literature. J Indian Acad Oral Med Radiol [serial online] 2017 [cited 2019 May 22];29:321-4. Available from: http://www.jiaomr.in/text.asp?2017/29/4/321/225561
| Introduction|| |
Salivary gland neoplasms represent <1% of all tumors and 3–5% of all head and neck neoplasms. Minor salivary gland tumors (MSGTs) are infrequent and fundamentally located in the palate (50%), lips (15%), cheek mucosa (12%), tongue (5%), and floor of the mouth (5%) among other regions. Despite their relatively low frequency, MSGTs represent a heterogeneous group of neoplasms, with a broad range of histological types and growth patterns. The MSGTs can appear at any age; the maximum incidence is in the fourth decade of life for benign lesions and in the fifth decade for malignant tumors. Characteristically, these lesions have been reported to be more frequent in women, though the proportion varies according to the histological type of tumor. The etiopathogenesis of MSGTs remains unclear.
The most frequent clinical presentation of benign MSGTs is in the form of an asymptomatic, single, well-delineated, smooth, and uniform nodular tumor with a normal overlying surface color. Benign lesions tend to be insidious and slow-growing, with an average course of 3–6 years, while malignant lesions are fast-growing and can ulcerate, become secondarily infected, and cause external or interstitial bleeding, giving rise to superficial telangiectasias. The diagnosis of MSGTs is based on the clinical history and physical exploration, supported by complementary techniques such as fine-needle aspiration biopsy (FNAB), magnetic resonance imaging (MRI), computed tomography (CT), etc. The combination of some of these techniques is able to offer a tentative diagnosis that must be confirmed by the corresponding intraoperative histopathological study.
MSGTs have a high recurrence rate (5–30%) when surgical removal is incomplete, and the possibility of malignant transformation must be taken into consideration. This capacity to relapse is related to the histopathological characteristics of the tumor, and particularly to the initial treatment provided. The present study describes four cases of MSGTs in palate with varied presentations, revealing benign and malignant characteristics of the same. A review of literature is also made regarding the clinical features, diagnosis and treatment modalities for the same.
| Case Reports|| |
A 52-year-old female patient presented with a palatal swelling of 30 years duration, which was asymptomatic, gradually progressing, and causing swallowing difficulty for the past 1 month [Figure 1]. On examination, the swelling was 1.5 × 2 cm along midline of palate, sessile, firm with diffuse brown pigmentation inferiorly. CT examination revealed a heterogeneously enhancing well-defined mass crossing midline in relation to hard palate with multiple small internal calcific foci. The lesion was provisionally diagnosed as minor salivary gland adenoma or other connective tissue benign tumors, and excisional biopsy was done. The histopathological report was suggestive of pleomorphic adenoma palate.
|Figure 1: (a) Well-defined intraoral swelling in relation to hard palate; (b) CT showing well-defined hypodense lesion with mild contrast enhancement in relation to palate; (c) Maxillary occlusal radiograph showing minimal bone involvement; (d) Excised biopsy specimen; and (e) Histopathological appearance of pleomorphic adenoma|
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A 40-year-old female patient complained of a slow-growing swelling of approximately 2 years duration involving her entire palate [Figure 2]. The lesion was asymptomatic, except for gradual increase in size, and patient presented with a typical “hot potato in mouth” speech. The clinical examination revealed a dome-shaped swelling on the palate crossing the midline. The swelling measured 5 × 5 cm in size. The mass had a bosselated surface, and the overlying mucosa was pale with pinpoint erythema in the center. The lesion was slightly lobulated, soft to firm, and nontender to palpation. On the basis of history and clinical examination, a provisional diagnosis of adenoma of the palate was made. Adenoid cystic carcinoma and other benign connective tissue tumors were included in the differential diagnosis. The patient was further subjected to routine blood and radiographic investigations, including occlusal radiograph, which did not reveal any abnormalities. CT scan revealed an isodense structure in the palate with no signs of bony erosion of the palatal region. Incisional biopsy was done and histopathological report was suggestive of pleomorphic adenoma palate. The mass was excised and histological diagnosis was confirmed. The patient was kept under close follow-up and no recurrence is noticed till now.
|Figure 2: (a) Intraoral swelling involving entire hard palate; (b) Excised biopsy specimen; (c) CT showing well-defined isodense lesion in relation to palate not involving bone; and (d) Histopathological appearance of pleomorphic adenoma|
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A 60-year-old female patient had a chief complaint of swelling on the left side of the face since 3 months [Figure 3]. On examination, a hard, nontender, diffuse swelling was present on the left middle third of the face measuring 5 × 4 cm in size, extending from the infraorbital rim to 3 cm above the left angle of the mandible superio-inferiorly and from the ala of the nose to zygoma of maxilla. Skin over the swelling was stretched and shiny. On palpation, it was nontender and hard in consistency. Intraoral examination revealed a single, diffuse-lobulated swelling over left upper alveolar ridge, 5 × 4 cm oval, extending from 23 to maxillary tuberosity and crossing midline of palate medially. The overlying mucosa was ulcerated and there was no sinus tract or pus discharge. Provisional diagnosis of minor salivary gland neoplasm was made. Hemangiopericytoma and carcinoma left maxilla were considered as differential diagnosis. Panoramic radiographs and maxillary topographic occlusal views revealed a lytic lesion involving left maxilla, obliterating sinus. Contrast enhancement was seen in CT. Incisional biopsy report was suggestive of mucoepidermoid carcinoma (MEC). The patient was referred to higher center for hemi-maxillectomy and radiotherapy.
|Figure 3: (a) Extraoral swelling on left side of face; (b) Intraoral ulcerated swelling extending from 23 to tuberosity region; (c and d) Lytic lesion obliterating left maxillary sinus; and (e) Histopathological appearance of mucoepidermoid carcinoma|
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A 10-year-old male presented with chief complaint of swelling on upper right back teeth region of the jaw since 1 year [Figure 4]. Swelling was initially small in size and gradually increased to attain the present size. On examination, there was a single swelling of 1.5 × 1.5 cm with smooth, well-defined borders in relation to hard palate right side. On palpation, it was soft in consistency, nontender, not freely movable. All the teeth were vital and aspiration was negative. Radiographs revealed a unilocular radiolucency with noncorticated well-defined margins in relation to incompletely formed root apex of 14 and 15. CT showed well-defined nonenhancing lesion over right-side hard palate not crossing midline. Provisional diagnosis of adenoma was made. Biopsy was suggestive of intermediate grade MEC right palate.
|Figure 4: (a) Intraoral swelling on right side of palate; (b) Maxillary lateral topographic view showing unilocular radiolucency in 14 and 15 region; (c) CT showing well-defined nonenhancing lesion over right side palate; and (d) Histopathological appearance of intermediate grade mucoepidermoid carcinoma|
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| Discussion|| |
Salivary gland tumors are a heterogeneous and rare group of lesions, especially when affecting the minor salivary glands. Generally, they affect major salivary glands, and rarely in about 10–15% cases, they affect minor salivary glands. The palate is the most frequent site for minor gland tumors (57%) followed by buccal, lingual, labial, and gingival glands. Pleomorphic adenoma is the most common benign MSGT, followed by myoepithelioma whereas MEC and adenoid cystic carcinoma are the most common malignant tumors. In our case series also, two of the discussed adenomas were of pleomorphic type only and rest were MECs. MSGTs are common in fourth to sixth decade of life, more commonly affecting female patients, nearly 62%.,
The time of progression was shorter for malignant lesions and the mean size of all the lesions was almost similar in our cases. The data were similar between benign and malignant neoplasm, confirming the difficulty in diagnosis of salivary gland tumors. Signs and symptoms can be related to tumor size and may vary according to the tumor site. Therefore, all suspected tumors of minor salivary glands require biopsy to avoid delays and errors in diagnosis. Clinically, it is not possible to differentiate malignant and benign tumors of minor salivary glands. Swelling is the most common sign of MSGTs. Difficulty in speaking and pain are the other signs and symptoms observed in benign and malignant tumors, again mostly depending on the size of lesion. In aggressive variants of MEC, bone resorption, tooth mobility, etc. may be manifested in radiographs, similar to our pediatric patient where there was significant bone resorption suggesting malignancy.
The differential diagnoses for this case include palatal abscess, odontogenic and nonodontogenic cysts, and other soft tissue tumors. Abscess can be ruled out because of loss of signs and symptoms of inflammation, whereas cysts are not firm in consistency. FNAB should be performed as an adjunct to diagnosis prior to definitive surgical treatment. CT or MRI should be considered when assessing for presence of bony erosion or soft tissue and nerve involvement. The histological pictures of pleomorphic adenomas vary. Pleomorphic adenomas of the minor salivary glands are similar to those in the major salivary glands and are composed of a mixture of epithelial and stromal elements. Three main histological subgroups have been identified: myxoid (80% stroma), cellular (myoepithelial predominant), and mixed (classic) type. Generally, treatment includes wide excision with 1 mm safety margins around the lesion. It should be diagnosed early as it causes disfigurement and loss of function.
Clinically, the majority of palatal MEC appears as firm, painless swellings, and may mimic mucoceles or vascular lesions. Clinical findings and investigations in the present case indicated a surface lesion. Blue to red color of the lesion may suggest it to be either of vascular or of salivary gland origin. When a compressible palatal mass is observed in adolescent, reactive and neoplastic lesions should be included in the differential diagnosis. The other minor salivary gland neoplasm, mainly pleomorphic adenoma, as well as benign and malignant mesenchymal tumor, should also be considered. A fluctuant light blue mass in an intraoral salivary gland bearing area, MEC, and mucoceles should be at the top of the list.
Histologically, MECs are divided into low-, intermediate-, and high-grade types, which correlate with clinical behavior. In the present case, a histopathological diagnosis confirmed the lesion to be of intermediate-grade MEC. The intermediate-grade MEC comprises solid rather than cystic architecture with more intermediate cells. The histologic grade of the MEC often reflects the clinical manifestations of the tumor. If there is any evidence of gross periosteal involvement or bone erosion, removal of a portion of the involving bone is necessary. High-grade tumors require more aggressive surgical approach with or without postoperative radiotherapy and chemotherapy. Furthermore, it should be considered that micro-marsupialization, cryosurgery, and laser therapy are contraindicated in the management of intraoral submucosal mass/nodules in children, particularly if the palate is involved. These kinds of treatments may result in local spread of the tumor, and more aggressive surgery may be needed.
| Conclusion|| |
Swellings in the palatal region resemble dental abscess and cyst, which can lead to unnecessary treatment and delay in diagnosis of true disease; hence, these kinds of swellings must be considered carefully and interdisciplinary approach will bring to a successful treatment.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
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