Objective: Myoepithelioma is a rare tumor, accounting for 1% of all salivary gland tumors. It clinically resembles pleomorphic adenoma in the palate, while on imaging modalities, such as computed tomography （CT） or magnetic resonance imaging （MRI）, its findings often correspond to those of a diverse range of diseases. Considerable attention is thus being given to the diagnosis of myoepithelioma based solely on its imaging findings.
Case: Here, we report a case of myoepithelioma of the left palate in a 13-year-old female. A 13×13-mm lump was palpable in the left hard palate. Axial CT showed an ovoid, expansile, hypodense lesion with well-circumscribed margins. The lesion exhibited signal hypointensity on T1-weighted imaging （repetition time ［TR］/echo time ［TE］: 500/7ms）, inhomogeneous signal hyperintensity on T2-weighted imaging （TR/TE: 5000/80ms）, and enhancement on contrast-enhanced T1-weighted imaging （TR/TE: 581/11ms）. The lesion was thus diagnosed as a benign salivary gland tumor, with a clinical diagnosis of pleomorphic adenoma. A histopathological examination performed after surgical resection resulted in a diagnosis of myoepithelioma.
Conclusion: Salivary gland tumors of the palate are often considered to show an increased frequency of malignancy, and their differential diagnoses must be carefully considered. However, myoepithelioma displays similar findings to a diverse range of diseases so its histopathological diagnosis might depend to a large degree on its imaging findings on MRI. It will be necessary to research the differential diagnoses of minor salivary gland tumors of the palate using various imaging modalities in the future.
