Mucoepidermoid carcinoma as a secondary malignancy in pediatric sarcoma

Children diagnosed with osteosarcoma (OS) and Ewing sarcoma (ES) have greatly benefited from the addition of alkylator therapy. However, with greater numbers of long-term survivors, the rising incidence of secondary malignant neoplasms (SMNs) is concerning. Herein we report on 2 patients with sarcoma who developed a case of secondary mucoepidermoid carcinoma after chemotherapy treatment without associated radiation therapy. To our knowledge, this is the first series of mucoepidermoid carcinomas arising in pediatric patients treated for sarcoma without radiotherapy.

Long-term survivors of OS and ES currently undergoing routine follow-up care were reviewed and noted for the development of a new secondary malignancy. Details of their initial evaluation, previous therapies, resection techniques, pathologic findings, and follow-up compose this report.

Two patients, a 17-year-old adolescent boy with OS and 16-year-old adolescent girl with ES, with secondary mucoepidermoid carcinoma of the parotid gland were identified. Both patients underwent primary resection and chemotherapy including alkylating agents, but neither received radiation. The mucoepidermoid carcinomas developed 27 months and 132 months after completion of therapy, respectively, and were noted on routine yearly follow-up. Fine-needle aspiration was nondiagnostic on each, and parotidectomy with preservation of the facial nerve was performed. Pathology revealed low-grade mucoepidermoid carcinoma with tumor extending to the deep margins for both lesions, and radiotherapy to the parotid bed was administered. There were no surgical complications. One patient is alive, without evidence of recurrent mucoepidermoid carcinoma after 4 years; the other recently completed radiotherapy and is disease-free after 12 months.

Primary mucoepidermoid carcinoma of the parotid gland accounts for less than 10% of all head and neck tumors in childhood. Previous series of secondary mucoepidermoid carcinoma have demonstrated an increased risk in patients with leukemia/lymphoma. This is the first reported series of parotid mucoepidermoid carcinomas occurring after sarcoma treatment without radiotherapy. A common link between the 2 patients may be the use of alkylating therapy.