Endocrine Abstracts

Background: Klinefelter syndrome (KS) is the commonest sex chromosomal disorder. Characteristic features include male phenotype with hypogonadism and progressive testicular failure, gynaecomastia and learning difficulties. The association between mediastinal germ cell tumours (GCT-M) and KS is well established, with KS occurring in 20% of GCT-M patients and the reported incidence of GCT-M in KS being 1.5 per 1000 (Nichols, 1991). Genital anomalies are also known to be rarely o...