|LETTER TO THE EDITOR
|Year : 2016 | Volume
| Issue : 1 | Page : 18-19
A rare carcinoma ex pleomorphic adenoma of the buccal minor salivary gland causing a therapeutic dilemma
YK Kini1, JV Kalburge2, VR Kharkar3
1 Department of Oral and Maxillofacial Surgery , Dr. D. Y. Patil Dental College, Nerul, Navi Mumbai , Maharashtra, India
2 Department of Oral and Maxillofacial Pathology, GDC, Jamnagar, Navi Mumbai , Maharashtra, India
3 Department of Oral and Maxillofacial Surgery, BVP Dental College, Kharghar, Navi Mumbai , Maharashtra, India
|Date of Web Publication||28-Apr-2016|
Y K Kini
Department of Oral and Maxillofacial Surgery , Dr. D. Y. Patil Dental College, Nerul, Navi Mumbai , Maharashtra
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Kini Y K, Kalburge J V, Kharkar V R. A rare carcinoma ex pleomorphic adenoma of the buccal minor salivary gland causing a therapeutic dilemma. Indian J Cancer 2016;53:18-9
|How to cite this URL:|
Kini Y K, Kalburge J V, Kharkar V R. A rare carcinoma ex pleomorphic adenoma of the buccal minor salivary gland causing a therapeutic dilemma. Indian J Cancer [serial online] 2016 [cited 2021 Jan 21];53:18-9. Available from: https://www.indianjcancer.com/text.asp?2016/53/1/18/180828
Malignant mixed tumors are usually classified as one of three main subtypes: (1) Carcinoma ex pleomorphic adenoma (CXPA), (2) true malignant mixed tumor (carcinosarcoma), and (3) metastasizing mixed tumor.  CXPA is defined as pleomorphic adenoma from which an epithelial malignancy is derived. CXPA is reported to represent approximately 3-5% of all major salivary gland neoplasms and 5-15% of major salivary gland malignancies., CXPA is exceedingly rare in the minor salivary glands of the oral cavity.
We present here a case of CXPA arising in the buccal mucosa.
A 17-year-old female reported to us with a slowly enlarging mass on the right side of the buccal mucosa [Figure 1]. She had first noticed a small swelling 6 months back. Since then, it had increased markedly in size. The mass was not painful and did not trouble her, except that it had become increasingly noticeable.
Bimanual palpation revealed a firm, mobile, 3-cm, well-circumscribed mass in the right buccal mucosa region lateral to the upper premolars. The mass could be felt in between the mucosa and skin. The overlying mucosa and skin were of normal color and texture [Figure 2]. Clear saliva was expressed from the right parotid duct. There was no trismus or any associated lymphadenopathy. The clinical features were highly suggestive of a benign lesion.
Ultrasonography showed a well-defined, round, predominantly hypo-echoic mass lying underneath the right buccinator muscle. A differential diagnosis of sebaceous cyst or epidermal cyst was suggested. Fine-needle aspiration cytology was suggestive of epidermal cyst. All other routine hematological investigations were within normal limits. The tumor was enucleated under general anesthesia [Figure 3]. On gross examination, the encapsulated lesion measured 4 × 2.5 cm, with a whitish, faintly lobulated surface [Figure 4].
Histopathological examination (×20, hematoxylin and eosin (H and E) stain) showed a neoplasm with an admixture of epithelial and stromal components. Tumor epithelial cells were arranged in the form of ducts containing eosinophilic material, islands, and sheets [Figure 5]. Outer myoepithelial cells were surrounded by a chondromyxoid stroma, consistent with pleomorphic adenoma.
On magnification (×40, H and E stain) certain areas showed tumor epithelial cells invading the fibrous capsule [Figure 6]. Cellular details revealed moderate nuclear pleomorphism, loss of chromatin, prominent nucleoli, and moderate mitotic activity. Keratin formation by epithelial cells was also seen [Figure 7]. Due to the presence of atypia and capsular infiltration, the diagnosis of minimal invasive variant of CXPA was made. This rare histopathological diagnosis warranted a therapeutic reconsideration as some of the margins showed infiltration. The patient was recalled after a month and wide local excision was done. The second histopathological report was free of tumor cells, and exhibited connective scar tissue. After a 1-year follow-up period, the patient is now symptomless and is showing no signs of recurrence.
About 1.6-7.5% of pleomorphic adenoma showed malignant changes in its natural course., Pleomorphic adenoma is very rarely reported in the minor salivary glands and CXPA involving the buccal minor salivary gland is even rarer. CXPAs are sub-classified into non-invasive, minimally invasive (about 1.5 mm penetration of the malignant component into the extra-capsular tissue), and invasive (more than 1.5 mm penetration into the extra-capsular tissue). Depending on this sub-classification, treatment may vary. However, due to the rarity of occurrence, it is not usually considered in the differential diagnosis as in our case where the histopathological finding necessitated a second surgery. We would therefore always advise an incisional biopsy followed by thorough histopathological evaluation and definitive radical 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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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]