Malignant myoepithelioma of the palate: a case report with review of the clinicopathological characteristics

Abstract

A malignant myoepithelioma is one of the rarest salivary gland neoplasms which may either arise de novo or develop within a preexisting pleomorphic adenoma or benign myoepithelioma. The parotid gland is the most common primary site and the palate the most common intra-oral site of occurrence. Herein is present a case of a malignant myoepithelioma arising in the hard palate of a 79-year-old woman. The lesion had been examined by biopsy at another hospital, and diagnosed as a poorly differentiated squamous cell carcinoma. The patient underwent a wide local tumor resection. Examination of the resection specimen showed the characteristic histopathological and immunohistochemical features of a malignant myoepithelioma. Five months after the operation, the patient was well without evidence of recurrence or metastasis.

Keywords: Malignant myoepithelioma; palate.

Fig. 1

Axial computed tomography scan showing a solid mass in the hard palate.

Fig. 2

Plasmacytoid and spindle-shaped cells, with pleomorphic nuclei and prominent nucleoli in a myxomatous stroma (H&E, original magnification×200).

Fig. 3

Noncohesive, infiltrative and widespread single tumor cells at the edge of the tumor (H&E, original magnification×100).

Fig. 4

(A) Tumor cells were diffusely and intensely positive for vimentin (original magnification×200) and (B) S-100 protein (original magnification×200).