|Year : 2022 | Volume
| Issue : 2 | Page : 231-233
Plasmacytoid myoepithelioma arising in hard palate – A rare case report
Trupti V Gaikwad1, Mahesh S Chavan1, Vikram V Khare1, Charusheela R Gore2
1 Department of Oral Medicine and Radiology, Dr. D Y Patil Dental College and Hospital, Pune, Maharashtra, India
2 Department of Pathology, Dr. D Y Patil Medical College, Hospital and Research Centre, Dr. D. Y. Patil Vidyapeeth, Pune, Maharashtra, India
|Date of Submission||28-Dec-2020|
|Date of Decision||19-Jul-2021|
|Date of Acceptance||24-Jul-2021|
|Date of Web Publication||22-Jun-2022|
Trupti V Gaikwad
Department of Oral Medicine and Radiology Dr D Y Patil Dental College and Hospital, Dr D Y Patil Vidyapeeth, Pune, Maharashtra
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Myoepithelioma, which is benign, is a salivary gland neoplasm representing 1.5% of all the neoplasms of salivary glands. The commonest location of its occurrence is parotid gland. In this condition, there is proliferation of myoepithelial cells arranged in cords, mantles, or nests. A 20-year-old woman presented with a well-circumscribed, asymptomatic swelling on the left half of the hard palate, which was gradually increasing in size for 10 years. A provisional diagnosis of pleomorphic adenoma was made. Computed tomography scan showed a well-defined soft tissue density lesion, which on histopathologic examination revealed a well-circumscribed, partially encapsulated neoplasm comprising monomorphic tumor cells in clusters and lobules with plasmacytoid characteristics. Therefore, it is necessary to consider myoepitheliomas also as one of the differential diagnoses while dealing with palatal swellings.
Keywords: Adenoma, myoepithelioma, pleomorphic
|How to cite this article:|
Gaikwad TV, Chavan MS, Khare VV, Gore CR. Plasmacytoid myoepithelioma arising in hard palate – A rare case report. J Indian Acad Oral Med Radiol 2022;34:231-3
|How to cite this URL:|
Gaikwad TV, Chavan MS, Khare VV, Gore CR. Plasmacytoid myoepithelioma arising in hard palate – A rare case report. J Indian Acad Oral Med Radiol [serial online] 2022 [cited 2022 Jul 1];34:231-3. Available from: https://www.jiaomr.in/text.asp?2022/34/2/231/347923
| Introduction|| |
Myoepithelioma is a benign neoplasm of the salivary glands, which was first described in 1943 by Sheldon. It occurs most commonly between the age of 30 and 50 years., Because of its aggressive nature, in 1991, the World Health Organization (WHO) classified it as a distinct entity.,, Clinically, myoepitheliomas are present as slow-growing, painless, firm submucosal masses. Four cellular components have been described based on the histopathologic features: spindle cells, plasmacytoid or hyaline cells, epithelioid cells, and clear cells. Vimentin and glial fibrillary acidic protein (GFAP) are strongly and diffusely expressed in most of myoepithelioma cases and are more reliable markers for these tumors. Because of the varying characteristics, myoepitheliomas present a diagnostic challenge. We present a case of plasmacytoid myoepithelioma arising from the hard palate in a female patient of 20 years of age.
| Patient Information|| |
An Indian female patient, 20 years old, reported to the dental OPD with a hard palate swelling on the left side for 10 years. The medical, family, and psychological histories were not relevant.
At 10 years of age, she noticed a small, pea-sized swelling in the same region with no associated symptoms. It slowly progressed to its current size during the next 10 years. The patient visited the OPD because of the discomfort caused while swallowing for 2 months [Table 1]. Intraoral examination revealed a solitary dome-shaped swelling on the left posterior one-third region of the hard palate, extending from the midline to the posterolateral aspect next to the teeth 26, 27, and 28. It was approximately 2.5 cm in diameter [Figure 1]. The borders of the swelling were well defined. The surface over the swelling appeared to be smooth. On palpation, it was firm in consistency, noncompressible, nonfluctuant, painless, and immobile. All the teeth were present from 1 to 7 in all the quadrants. Based on the clinical findings, a provisional diagnosis of pleomorphic adenoma was given.
|Figure 1: Clinical appearance of the lesion: dome shaped with well-defined borders|
Click here to view
Routine radiographs showed no abnormality [Figure 2]a. Based on it, ameloblastoma, mucoepidermoid carcinoma, lymphoma, and neurinoma were considered as differential diagnoses. A computed tomography (CT) scan was advised (plain and with contrast), which showed a well-defined soft tissue density lesion measuring about 24 mm × 22 mm × 21 mm, arising from the hard palate [Figure 2]b,[Figure 2]c,[Figure 2]d,[Figure 2]e,[Figure 2]f,[Figure 2]g. Therefore, a radiographic diagnosis of benign non-odontogenic cyst of the palate was given. Find needle aspiration cytology (FNAC) revealed red blood cells (RBCs) and a few pus cells.
|Figure 2: (a) Occlusal radiograph showing no abnormality. (b–g) Contrast-enhanced CT scan showing well-defined soft tissue density arising from the palate. CT=Computed tomography|
Click here to view
Complete excision of the lesion was done along with primary closure.
Follow-up and outcome
Gross examination of the excised lesion revealed a well-circumscribed mass with smooth outlines measuring approximately 2.3 × 2 cm [Figure 3]a. Histopathologic examination of the lesion showed a well-circumscribed, partially encapsulated neoplasm comprising monomorphic tumor cells in clusters and lobules. Tumor cells had moderate eosinophilic cytoplasm and mildly pleomorphic, eccentric vesicular nuclei with inconspicuous nucleoli [Figure 3]b. In immunohistochemical analysis, S-100 protein and desmin were negative [Figure 3]c, GFAP was focally positive [Figure 3]d, and vimentin was diffusely positive [Figure 3]e. All these findings suggested plasmacytoid myoepithelioma.
|Figure 3: (a) Excised specimen of lesion measuring approx. 2.3 x 2 cm. (b) Well-circumscribed proliferation of sheets, islands, and strings of tumor cells showing moderate eosinophilic cytoplasm and mildly pleomorphic and eccentric vesicular nuclei (H&E, 400x). (c) Immunohistochemistry showing S-100 negativity, 10x. (d) Immunohistochemistry showing GFAP focal positivity, 10x. (e) Immunohistochemistry showing vimentin diffuse positivity, 10x. GFAP = glial fibrillary acidic protein, H and E = hematoxylin and eosin|
Click here to view
After 2 weeks, the patient was recalled to check healing, which was found to be uneventful. The patient is being observed with regular follow-up.
| Discussion|| |
Myoepithelioma is a rare tumor that is a challenging case to diagnose based only on clinical examination because of its infrequency and multiplicity of histopathology. Myoepitheliomas are basically tumors composed of myoepithelial cells which participate in some neoplastic processes like tumor cell differentiation, invasion, angiogenesis, and synthesis of basal membrane. The palate is the most frequent site for minor gland tumors (57%). Kim et al. reported two cases originating in the soft palate in an elderly man and a woman. In our case, the hard palate was affected. Myoepitheliomas, as seen in other reports,, are usually present as a slow-growing submucosal mass that is asymptomatic. The present case also showed similar clinical features. A case reported by Patel et al. in an 81-year-old man showed a very long-standing symptomatic swelling covering the entire maxilla, causing breathing and masticatory difficulties.
It has been proposed by WHO that a neoplasm must be named myoepithelioma if it contains less than 5% of the ductal components. Also, the aggressive nature of myoepitheliomas can help differentiate them from pleomorphic adenoma. Other differential diagnoses of myoepitheliomas include hemangiomas, neurinomas, metastatic tumors, malignant tumors, solitary fibrous tumor, lymphoma, leiomyoma, hemangiopericytoma, tumors of the nerve sheath, leiomyosarcoma, fibrous histiocytoma, and few inflammatory diseases. Biopsy plays an important role in confirmation of the diagnosis. The myoepithelial cells are round or ovoid with eosinophilic cytoplasm and eccentric nucleus. A similar cell type was seen in our case. Characteristic immunoreactivity is shown by myoepithelial cells for S-100, cytokeratin, calponin, myosin, smooth muscle actin, carcinoembryonic antigen, vimentin, and GFAP. Although in different cases of myoepitheliomas the immunoreactivity for various proteins is variable, in the presented case, vimentin and GFAP were positive. Many other studies have shown S-100, vimentin, and GFAP positivity along with smooth muscle actin (α-SMA) and cytokeratin 14 (CK14) negativity. Although the immunohistochemical analysis of the cytoplasmic filament expression is important for confirmation of the origin of myoepithelial tumor cells, the final diagnosis of the tumor is completely based on histological features of the cells. Complete surgical excision of the lesion including wide margins surrounding the lesion is recommended. There is no risk of recurrence even after 10 years of surgery.
| Conclusion|| |
Plasmacytoid myoepithelioma, a rare tumor of salivary glands, is a painless and slow-growing lesion that most commonly occurs in the minor salivary glands. Histopathologic findings are necessary for a definitive diagnosis. Considering myoepithelioma as one of the differential diagnoses is important while dealing with any case of palatal swelling.
Patient consent was obtained to use the relevant clinical details and images for the scientific publication purpose without revealing the identity.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Zormpa MT, Sarigelou AS, Eleftheriou AN, Assimaki AS, Kolokotronis AE. Plasmacytoid myoepithelioma of the palate: Case report. Head Neck Pathol 2011;5:154-8.
Mehta K, Bhatia G, Mehta H. Plasmacytoid myoepithelioma of hard palate in pregnancy: An extremely rare case. Int J Appl Dent Sci 2017;3:185-7.
Yogee AN, Choudhary R, Mathur N, Bhuie HS. Myoepithelioma of soft palate: A case report and review of literature. Int J Otorhinolaryngol Clin 2016;8:32-4.
Jafarian AH, Omidi AA, Roshan NM, Montazer M, Joushan B. Recurrent extensive plasmacytoid myoepithelioma of the sinonasal cavity. J Res Med Sci 2012;17:979-82.
Dardick I. Myoepithelioma: Definitions and diagnostic criteria. Ultrastruct Pathol 1995;19:335-45.
Yadav AK, Nadarajah J, Chandrashekhara SH, Tambade VD, Acharya S. Myoepithelioma of the soft palate: A case report. Case Rep Otolaryngol 2013;2013:642806.
Srivastava A, Agarwal R, Channaiah SG, Chandra A. Immunohistochemical analysis of plasmacytoid myoepithelioma of minor salivary glands: A case report with review of literature. J Indian Acad Oral Med Radiol 2016;28:433-6. [Full text]
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. [Full text]
Kim HS, Lee WM, Choi SM. Myoepitheliomas of the soft palate: Helical CT findings in two patients. Korean J Radiol 2007;8:552-5.
Patel PN, Thennavan A, Narayanaswamy V, Radhakrishnan R. Plasmacytoid myoepithelioma: Diagnostic algorithm and a tailored therapeutic protocol for a geriatric individual. J Oral Maxillofac Surg Med Pathol 2015;27:737-40.
Cuadra Zelaya F, Quezada Rivera D, Tapia Vazquez JL, Paez Valencia C, Gaitán Cepeda LA. Plasmacytoid myoepithelioma of the palate. Report of one case and review of the literature. Med Oral Patol Oral Cir Bucal 2007;12:E552-5.
[Figure 1], [Figure 2], [Figure 3]