Parotid Myoepithelial Carcinoma in a Pediatric Patient with Multiple Recurrences: Case Report.

Myoepithelial carcinoma of the salivary glands is a rare entity, with scarce amount of case reports in the literature. Due to its infrequency, its diagnosis is usually difficult and uncertain. Although there are reports of locoregional recurrences and distant metastases, its low incidence and varied biological behavior limits the clinical evidence that can be used to predict the prognosis and determine the course of treatment. We present a 23-year-old female patient without past medical history with an initial 1-year history of volume increase in the right parotid region of tumor aspect and painful on palpation. As a malignancy was suspected, a total parotidectomy was performed, reporting in the deep lobe a parotid myoepithelial carcinoma with vascular and neural invasion, negative borders, and 3-9 negative regional nodes. During her 16-year clinical evolution, she presented approximately every 2 years and a total of 9 locoregional recurrences and hepatic metastases, including cervical lymphoid nodules, temporal bone, frontal bone, and temporal fossa. Those recurrences have been treated with coordinated efforts between repeated external radiotherapy, chemotherapy, and multiple surgical resections. Myoepithelial tumors represent only 1.0-1.5% of all salivary gland tumors. The literature reports suggest a high incidence of locoregional recurrences and distant metastases in de novo myoepithelial carcinomas. Due to its rarity, treatment continues to be based on the experience of medical staff.