Mucoepidermoid carcinoma of the parotid as a second malignant neoplasm in children.

Second malignant neoplasms (SMN) in children who have survived their initial encounter with a malignancy have emerged as one of the most troublesome complications in pediatric oncology. Some estimates indicate that as many as 8% to 12% of patients will develop a SMN during a 20-year period. The majority of SMN are osteosarcomas, spindle cell and pleomorphic sarcomas of soft tissues, and hematolymphoid malignancies. We present the clinical and pathologic findings for two children with treated acute leukemias in whom well-differentiated mucoepidermoid carcinomas of the parotid gland developed 6 and 9 years after multidrug chemotherapy and cranial irradiation. Although mucoepidermoid carcinoma has been reported as a complication in adults who received low-dose irradiation as children, these two cases are unique as SMN in the pediatric age population.