Precocious sexual development in boys
In boys who present with signs of sexual development before the age of 9, the key to further investigation and the diagnosis is the demonstration of testicular enlargement. If this is present, there is usually abnormal pubertal gonadotropin secretion often secondary to a CNS tumour (gonadotropin dependant precocious puberty). Primary hypothyroidism can, however, rarely present in this way. In the absence of testicular enlargement, one needs to exclude pathological from normal variations. Adrenarche which occurs in boys on average at 7 years is a normal variant and may cause some pubic hair growth. The source of excess androgens is usually adrenal as auto-regulation of the testes (testotoxicosis) is extremely rare (gonadotropin independent precocious puberty).