Malignant myoepithelioma of palate
A 50-year-old female reported with the complaint of a painless mass in the hard palate for the last 2 years, which progressively increased to the present size over the period of time. On examination, there was a smooth, bulging, 6 cm × 5 cm in size sessile mass in the left palatal region crossing the midline with areas of ulcerations []. The swelling was soft to firm, non-tender, and negative on aspiration. Standard occlusal radiograph of the maxilla revealed no erosion of the underlying bone []. After appropriate medical history, routine hemogram, and informed patient consent, incisional biopsy was performed from the representative area under local anesthesia, and further histopathological examination was performed.\nHistopathological section stained with routine hematoxylin and eosin under the scanner view revealed intact stratified squamous surface epithelium with a cluster of small duct-like spaces lined by small deeply staining cells just beneath the epithelium. Deeper part of the section revealed pleomorphic large round cells with scanty eosinophilic cytoplasm and eccentrically placed nuclei in sheets along with areas of hyperchromatic spindle cells as shown in []. Under higher magnification (40×), solid sheets of large, highly pleomorphic cells with hyaline-like cytoplasm, eccentrically placed nuclei, and scattered nucleoli were observed. Frequent mitotic figures were encountered. The stroma was scanty and avascular and showed occasional eosinophilic structures with fine needle-like processes radiating outwards as shown in [].\nFurther collagenous nature of the spherules was confirmed with Von Geison's stain, which stained red as shown in inset. Immunohistochemical analysis showed immunoreactivity for cytokeratin 5, 6, alpha smooth muscle actin, calponin as shown in [Figure –] but negative to epithelial membrane antigen (EMA), and Ki 67, respectively. So, the present case suitably fits into the criteria set by WHO 2005 guidelines set for malignant myoepithelioma, according to which, immunoreactivity for cytokeratin and at least one of the myoepithelial markers, including smooth muscle actin, GFAP, CD10, calponin, and smooth muscle myosin heavy chain, is required for diagnosis.[]\nDifferential diagnosis includes pleomorphic adenoma ex-carcinoma and metastatic melanoma[]\nAfter the diagnosis, the patient was referred to the department of oncosurgery where wide surgical excision of the tumor mass was performed. Post-operative histopathological diagnosis confirmed the initial diagnosis. No other adjuvant radiotherapy or chemotherapy was delivered. Patient reported with no signs of local or regional recurrence 6 months post-operatively.