Tamoxifen-associated hirsutism: an unusual side effect in a 5-year-old girl with McCune-Albright syndrome.

Tamoxifen, a selective estrogen receptor modulator, has been used in the treatment of peripheral precocious puberty. A 5-year and 3-month-old girl, diagnosed with McCune-Albright syndrome, came in with abnormal hair growth approximately 2 months after the initiation of tamoxifen. The pattern of terminal hair on the skin following the administration of the drug and the exclusion of other causes suggested tamoxifen-induced hirsutism.