Masculinising/feminizing effect
Some types of testicular tumors produce hormones such as beta-human chorionic gonadotrophin(beta hCG) or testosterone. Beta hCG is produced by a Sertoli cell tumor, causing a feminizing effect (growth of breasts, known as gynecomastia), and testosterone is produced by Leydig cell tumors, which can cause masculinizing effects (early puberty in males).