Cutaneous syncytial myoepithelioma: A case report with emphasis on the differential diagnosis of problematic dermal tumors.

Cutaneous myoepithelioma is a peculiar and recently recognized neoplasm exhibiting purely myoepithelial differentiation. These lesions affect different areas of the body, and are characterized by heterogenous morphological and immunophenotypical features. The majority of cutaneous myoepitheliomas behave in a benign fashion, however, the risk for local recurrence is higher with incomplete resection. A relatively newly described variant of myoepithelioma exhibits syncytial cytological features. The current study reports a case of cutaneous syncytial myoepithelioma presenting as a painless and papular skin lesion. The presence of the Ewing sarcoma RNA-binding protein 1 gene rearrangement in the present case supported the diagnosis of a myoepithelial tumor. The patient subsequently underwent local excision of the tumor and was followed up twice in the year after surgery. At the time of writing, the patient was alive and no recurrences had been identified. Furthermore, the current study discusses how this myoepithelial neoplasm may be distinguished from other problematic spindle or epithelioid cell tumors, particularly superficial dermal lesions.