|Year : 2017 | Volume
| Issue : 3 | Page : 217-219
Pleomorphic adenoma: An unusual presentation on upper lip - A case report
Deena C Thomas, Vivek V Nair, Sunila Thomas
Department of Oral Medicine and Radiology, PMS College of Dental Science and Research, Trivandrum, Kerala, India
|Date of Submission||30-Jan-2017|
|Date of Acceptance||08-Nov-2017|
|Date of Web Publication||20-Nov-2017|
Vivek V Nair
Department of Oral Medicine and Radiology, PMS College of Dental Science and Research, Trivandrum, Kerala
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Pleomorphic adenoma (PA) is a benign epithelial tumor arising from the major salivary glands. Only 6.4% occur in minor salivary glands. Among minor salivary glands, palate is considered as the most common intraoral site, followed by cheek and very rarely in upper lip. Clinically, the lesion occurs as a painless, slow-growing, dome-shaped mass with a smooth surface. The microscopic examination shows a mixture of glandular epithelial and myoepithelial cells within a mesenchyme-like background. The treatment consists of surgical excision down to the underlying periosteum. This case report describes a rare and unusual lesion found in a 12-year-old male patient, which was diagnosed as PA of the minor salivary gland in the upper lip.
Keywords: Benign, pleomorphic adenoma, salivary gland neoplasm, upper lip
|How to cite this article:|
Thomas DC, Nair VV, Thomas S. Pleomorphic adenoma: An unusual presentation on upper lip - A case report. J Indian Acad Oral Med Radiol 2017;29:217-9
|How to cite this URL:|
Thomas DC, Nair VV, Thomas S. Pleomorphic adenoma: An unusual presentation on upper lip - A case report. J Indian Acad Oral Med Radiol [serial online] 2017 [cited 2020 Aug 11];29:217-9. Available from: http://www.jiaomr.in/text.asp?2017/29/3/217/218716
| Introduction|| |
Pleomorphic adenoma (PA) is the most common benign tumor of salivary glands., Also known as “mixed tumor, salivary gland type” because of wide cytomorphologic diversity. It affects mainly major salivary glands, with 6.4% cases in minor salivary gland. Among minor salivary glands, common site is palate, followed by upper lip and buccal mucosa. Eighty percent of minor salivary gland tumors in lip are benign. Average age in children is 10.5 years  with asymptomatic slow growth and unknown etiology. This case report describes diagnosis and management of an asymptomatic, slowly growing, PA in the upper lip of a child.
| Case Report|| |
A 12-year-old male patient presented at the Department of Oral Medicine and Radiology complaining of a painless swelling in his upper lip since 1 year. The patient had history of facial trauma at 4 years of age. He noticed this swelling while smiling. He did not have pain, tenderness, or discharge associated with the swelling. The patient had no difficulty in mouth opening and functional disability. The patient noted slight increase in size during past 6 months. There was no history of similar swelling elsewhere in the body and no relevant medical and dental history.
No abnormalities or facial asymmetry was detected on extraoral examination. On intraoral examination, a well-defined dome shaped swelling 1 × 1 cm size and same color of mucosa was noted on left side of upper lip in relation to 21, 22, and 23 region. On palpation it was non-tender, firm, non-compressible, non-reducible, and non-pulsatile [Figure 1]. Based on the presence of a slowly growing painless mass located in the upper lip of a child, a benign salivary gland tumor was considered as the provisional diagnosis. The differential diagnoses of fibrosed mucocele, fibrolipoma, and monomorphic adenoma was made. Excision was performed under local anesthesia and the specimen was sent for histopathological examination [Figure 2]. The postoperative period was uneventful.
Surgical specimen composed of connective tissue covered by a bit of moderately hyperplastic surface stratified squamous epithelium at the center. Wide subepithelial connective tissue contained lobules of normal minor salivary gland, predominantly mucous acini. It was separated by a well-defined thin fibrous capsule from the nodular tumor mass which was made up of epithelial and mesenchymal elements. The epithelial components were arranged in sheets, interlacing tubules, and strands also in ductal pattern, where the lumen was filled with mucinous material. Large cystic areas filled with mucin were visible near the capsule. Squamous metaplasia of glandular epithelium was an extensive feature with formation of well-formed keratin pearls in all sections. The supporting stromal tissue was loose, but moderately cellular. It exhibited areas of myxoid and osseous tissue. These features were observed in all sections. However, the cut end of nodular mass lacked a fibrous wall and there was no normal connective tissue in this region [Figure 3], [Figure 4], and [Figure 5].
|Figure 3: 40× shows loose collagenous connective tissue exhibiting myoepithelial cells|
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|Figure 4: 10× shows cystic areas and squamous metaplasia with keratin pearl formation|
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After clinicocytopathological correlation, a final diagnosis of PA of minor salivary gland was rendered and there was no evidence of malignancy. The postoperative healing was uneventful. The patient is under regular follow-up for last 4 months, with no evidence of recurrence.
| Discussion|| |
In head and neck neoplasm, salivary gland tumors are rare and constitute 3–5%. In 10–15% cases it affects minor salivary gland. Tumors arising from minor salivary glands are uncommon in children. “Pleomorphic adenoma” is a term derived by Wills, due to its unusual histological pattern. As epithelial and mesenchymal components are present, it is known as benign mixed tumor.,
In children PA occurs between 7 years and 16 years of age with an average age of 10.5 years, while in adults peak incidence is in third and fourth decade of life. PA originating from lips usually tends to occur in early age. Even though minor salivary gland neoplasms are rare entities in children, there are few reports of PA located in the upper lip. Jorge et al. and Lotufo et al. reported PA of upper lip in three patients under the age of 18 years.
It is commonly seen in females compared to males (7:3)., The most frequent site of PA of minor salivary glands is hard and soft palate (42–68%), followed by upper lip [10%] and rarely in tongue, floor of the mouth, and retromolar area. Usually lesions in upper lip are benign, whereas malignant lesions tend to occur in lower lip. This may be due to difference in embryonic development between upper and lower lips. Ninety two percent of upper lip tumors are monomorphic adenoma (canalicular adenoma and basal cell adenoma) and PA. PA usually presents as slow growing painless nodular firm mass which is freely mobile,, so as in our case. Correlating with clinical findings and literature, PA was considered in this child with asymptomatic slow growing swelling on the upper lip. The malignant transformation may occur in 5% of cases.
The histological pictures of PAs vary, showing a mixture of epithelial, and myoepithelial elements, within a background stroma that may be mucoid, myxoid, chondroid, or fibroid. The epithelial elements consist of polygonal, and spindle or stellate shaped cells, grouped in duct-like structures, or as sheets or interlacing strands. In this case, extensive squamous metaplasia of glandular epithelium with well-formed keratin pearls was noted. The squamous metaplasia can potentially occur extensively in PA and should be distinguished from a squamous cell carcinoma. PA with extensive squamous metaplasia and keratin cyst formations can pose a significant diagnostic challenge. However, misdiagnosis leading to aggressive treatment should be avoided, keeping in view that squamous metaplasia is seen in 20% cases of PA. Such cases should be subjected to immunochemistry for confirmatory diagnosis.
Treatment for PA is excision with normal margins due to high recurrence rate and malignant potential. The reason for recurrence is rupture of tumor capsule or incomplete excision during the procedure and leaving behind live residual tumor cells. The recurrence rate of PA is 2–44%. PA has excellent prognosis with a cure rate of 95%. Close follow-up is needed, so our case is also being followed-up due to risk of recurrence.
| Conclusion|| |
PA, although rare should be considered in differential diagnosis of upper lip lesions. The presence of an asymptomatic slow growing nodular mass in the upper lip in a young child should alert clinicians of the possibility of PA, as in this case. The squamous metaplasia in PA of upper lip in this child makes this case an unusual presentation. The diagnosis and treatment at an early stage can prevent further complication. Keeping in mind that PA can undergo malignant transformation and recurrence, the lesion should undergo wide excision and regular follow-up.
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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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]