Mediastinal Germ Cell Tumours (MGCT) in Children and Adolescents: Age Correlates with Histological Differentiation, Genetic Profiles and Clinical Outcome

The aim of this study was to evaluate the influence of age on biology and clinical outcome of MGCTs in children and adolescents. Between 1983 and 2000, 67 patients (median age 4 years, range neonate-26 years; 35 male, 32 females) were prospectively enrolled onto the German cooperative protocols of nontesticular GCTs in children and adolescents. Median follow-up was 29 (range 1–166) months. Histological diagnosis was seminoma in three patients, all of whom were older than 10 years. The incidence of teratoma differentiated was highest among neonates; only four of 26 patients were older than 10 years. Of 38 patients with malignant nonseminomatous MGCTs, 17 were adolescents (16 male, 1 female). Two patients had Klinefelter’s syndrome. Girls predominated (15 to 6) among infants with secreting MGCTs. During infancy, yolk sac tumour (YST) was the exclusive malignant histology, whereas in adolescence, mixed malignant GCTs with embryonal carcinoma, seminoma and choriocarcinoma components also occurred.