Association between prognosis and complete resection in primary cutaneous myoepithelial carcinoma: two case presentations and literature review.

Myoepithelial carcinoma is a rare tumor that occurs in the salivary glands. Therefore, primary cutaneous myoepithelial carcinoma is extremely rare. The malignancy of this tumor is due to its aggressive nature and high metastatic potential. Despite the general consideration that primary cutaneous myoepithelial carcinoma has a poor prognosis, there are few available prognostic data. Herein, we report two cases of primary cutaneous myoepithelial carcinoma to expand the literature on the clinical and pathological characteristics of this disease. In case 1, the tumor was completely resected and sentinel lymph node biopsy was performed, resulting in long-term survival. In contrast, case 2 progressed aggressively with multiple bone metastases despite treatment with docetaxel chemotherapy, and the patient ultimately died of the disease. Only 14 cases, including the present two cases, of primary cutaneous myoepithelial carcinoma have been reported to date. Overall, patients with clinical regional or distant metastases show a severe clinical course. Nevertheless, even in cases of inappropriate resection or local recurrence, if complete resection is ultimately achieved prior to clinical metastasis, the prognosis is good and survival is prolonged. Therefore, obtaining complete resection appears to be the most important treatment strategy for primary cutaneous myoepithelial carcinoma.