Effects of human growth hormone therapy on melanocytic naevi

Melanocytic naevi may grow more rapidly during human growth hormone (hGH) therapy. With standardised skin photographs, the growth rate of the naevi was two-fold greater in 14 hypopituitary and 5 Turner's syndrome girls treated with hGH than in untreated patients or controls. HMB-45 immunoreactivity, a marker of stimulated melanocytes, was absent in naevi from 18 of 19 individuals not treated with hGH, including 5 Turner's syndrome patients studied 2-43 months after stopping hGH. In naevi from 39 hGH-treated patients, 22 showed unusual HMB-45 reactivity in dermal naevocytes. During administration of hGH, melanocytic naevi grow faster and there is reversible stimulation of naevocytes.