Myoepithelioma and malignant myoepithelioma arising from the salivary gland: computed tomography and magnetic resonance findings.
ABSTRACT We report the CT and MRI appearance of myoepithelioma and malignant myoepithelioma arising from accessory salivary glands of the soft palate and the submandibular gland. Correlation of the imaging features and histologic finding is presented. Radiologists should bear in mind that myoepithelioma and malignant myoepithelioma are included in radiological differential diagnosis of head and neck tumours.
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ABSTRACT: Malignant myoepithelioma (MME) of the salivary gland, also known as myoepithelial carcinoma, is rare and its biologic behavior has not been clarified fully. Ten cases of MME were analyzed for their clinicopathologic features and immunohistochemical characteristics, focusing on prognostic factors and tumor differentiation. In addition, six cases of benign myoepithelioma (BME) also were examined for comparison. The ten patients with MME (3 men and 7 women) ranged in age from 48-81 years (mean, 61.9 years). Seven cases of MME arose in the parotid salivary gland, two in the submandibular salivary gland, and one in minor salivary glands of the soft palate. In the current series, the incidence of MME was 0.45% among 1945 cases of major salivary gland tumors. Seven cases of MME developed from a benign preexisting tumor (six in pleomorphic adenoma and one in BME). Four of nine patients with MME died of the disease and two patients developed a recurrence. It was shown that MMEs were comprised of one cell type or a combination of two cell populations; these included, in order of incidence, epithelioid, spindle, and plasmacytoid cells. Patients with MME with marked cellular pleomorphism and perineural invasion had a poor prognosis. Immunohistochemically, putative myoepithelial markers such as muscle actins, cytokeratin 14, vimentin, and calponin, and S-100 protein were expressed highly in MME. High and low molecular weight cytokeratins and epithelial membrane antigen also frequently were positive in MME. p53 expression was observed in five MME cases, four of which either recurred or were fatal. Cellular proliferative activity assessed by mitotic count and the Ki-67 labeling index was significantly higher in MME cases than in BME cases. In limited cases, such cellular proliferative activity was shown to have prognostic value. Ultrastructurally, the tumor cells displayed certain myoepithelial characteristics. MME is a rare salivary gland tumor showing clinicopathologic diversity and presenting with various stages of myoepithelial differentiation. Histologic aggressiveness, marked cellular pleomorphism, p53 expression, and high cell proliferative activity were found to be correlated with a poor clinical outcome.Cancer 11/1998; 83(7):1292-9. · 5.20 Impact Factor
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ABSTRACT: We report CT and MRI bindings in two cases of acinic cell carcinoma of the parotid glands which behaved differently on T2-weighted images. Differences in signal intensities were considered to reflect the histology of the lesion, although a histological diagnosis could not be made on imaging grounds alone.Neuroradiology 11/1996; 38(7):675-9. · 2.70 Impact Factor
- Acta Radiologica. 01/2000; 41(5):417-419.