The mechanism of action of pineal cysts leading to CPP is speculated to be as follows (27): (1) GnRH pulse suppression is eliminated due to compression of the hypothalamus by the cyst; (2) the pineal cyst adversely affects melatonin secretion, resulting in reduced inhibition of the HPGA and increased gonadotropin secretion; (3) the pineal cyst secretes gonadotropin or gonadotropin-like substances; and (4) substances conducive to the secretion of GnRH analogs are released. Here, GNRH1 is linked to cyst.