OBJECTIVE: Description of 4 cases of breast development in prepubertal girls treated with recombinant human growth hormone (rhGH). PATIENTS AND METHODS: Four prepubertal girls with short stature: 2 with Turner's syndrome (TS) and 2 with growth hormone deficiency (GHD). Breast development (Tanner II and III) was detected from ages 5.6 to 7.7 years and bone ages from 5.7 to 6.9 years, from 2 to 60 months after starting rhGH treatment doses of 0.1- 0.15U/kg/d. Breast development had disappeared 8 to 15 months after have been noted in all patients. Three patients were submitted to GnRH test that showed a prepubertal LH response. DISCUSSION: Prepubertal breast development has been reported in boys after rhGH treatment, but not in prepubertal girls. CONCLUSION: rhGH can induce transient breast development, even in girls, without activation of the hypothalamic-pituitary-gonadal axis and these patients do not need suppression of puberty.
Breast development; Thelarche; Growth hormone therapy