OBJECTIVE: To report an extremely rare case of a malignant tumor of the parotid gland. This disease comprises 1-3% of all malignant head and neck tumors. In the pediatric population, 10% of all tumors are salivary glands, 88.5% are benign and 22.5% malignant, with a predominance of mucoepidermoid carcinomas. CASE REPORT: An 11-year-old boy presented with a 1-year history of slow and progressively growing nodule in the cervical region, associated with pain on palpation. Physical examination revealed a 1.5-cm firm nodular lesion in the deep lobe of the left parotid gland. Fine needle aspiration biopsy (FNAB) diagnosed a pleomorphic adenoma of the parotid gland. Magnetic resonance imaging showed a heterogeneous irregular lesion in the left parotid with 2 adjacent enlarged lymph nodes. Total parotidectomy was performed on May 6, 2013. The pathologic diagnosis was low-grade mucoepidermoid carcinoma, according to the classification of OMS, 1.5 x 1.0 cm, with perineural invasion, positive margins, and 3 lymph nodes free of cancer, AJCC staging pt1 pN0 pmx. CONCLUSION: Mucoepidermoid carcinoma is the most common malignant tumor of the salivary gland in children. Low-grade mucoepidermoid carcinoma has a very good prognosis. It can mimic the clinical features of a benign tumor, such as that seen in the present case. FNAB can also yield false negative results, as seen here, despite the fact that it has high accuracy (87-96%), specificity, and sensitivity.
