Primary mediastinal malignancies in children: report of 22 patients and comparison to 197 adults.

PURPOSE Examine a contemporary series of patients with primary pediatric malignant mediastinal tumors and determine epidemiology, histology, treatment, and survival. Patients and Methods. All malignancies diagnosed between January 1, 1973 and December 31, 1995 were analyzed. RESULTS Twenty-two patients, age 18 years or less, with pediatric primary mediastinal malignancies were identified from a database of 110,284 patients with primary malignancies. During the same period, 197 adult patients with primary mediastinal malignancies were identified. Fifty-nine percent of the pediatric patients were male. Median age was 11 years. Lymphoma was present in 55%, neurogenic malignancies in 23%, malignant germ cell tumors in 18%, and sarcoma in 5%. Neurogenic tumors presented in infants and lymphomas and germ cell tumors presented in teens (p = 0.005). In treated children, surgery was used more often in neurogenic tumors and germ cell tumors than in lymphomas (p = 0.002). Five-year survival was 74% for lymphomas, 67% for neurogenic tumors, 25% for germ cell tumors, and 61% overall (p = 0.23). Compared to adults, children had more neurogenic tumors (p < 0.001) and fewer thymomas (p = 0.0499). There were no significant differences in staging or survival between children and adults. CONCLUSIONS Pediatric mediastinal malignancies occurred with a frequency of 1/5,013 patients with malignant tumors. Lymphoma, neurogenic tumors, and germ cell tumors predominated. Compared to adults, children had more neurogenic tumors and fewer thymomas. Within the pediatric group, differences were found in age of presentation between histologic groups. These differences between adults and children, and between infants and teens, should be considered when evaluating a patient suspected of having mediastinal malignancy.