Vaginal bleeding in a 4-month-old preterm girl: extreme minipuberty mimicking central precocious puberty.

We present a 4-month-old girl who showed vaginal bleeding and breast development. She was born preterm at 25 weeks and 4 days of gestation. Luteinizing hormone and follicle-stimulating hormone levels were extremely elevated. Magnetic resonance imaging showed a lesion of unknown nature in the pituitary gland, most likely a Rathke's cleft cyst. Because central precocious puberty (CPP) was suspected, a gonadotropin-releasing hormone analogue was started. At the age of 18 months, the treatment was stopped. Thereafter, no signs of puberty developed. The pituitary lesion remained unchanged. Therefore, the initial diagnosis of CPP was incorrect, and instead, an extreme minipuberty had occurred. If treatment for idiopathic CPP in girls younger than 2 years is started, we recommend the treatment be stopped after a certain period, for reevaluation of the diagnosis of CPP.