📊 Definitions
• Precocious puberty: onset of secondary sexual characteristics before age 8 years (or before 7 in African American girls)
• Isosexual: female sex characteristics; heterosexual: virilization (male characteristics)
• Premature thelarche: isolated breast development (no other signs)
• Premature adrenarche: isolated pubic/axillary hair
🧠 Central Precocious Puberty (CPP) – Gonadotropin-Dependent
• Most common form (idiopathic, esp. girls). MRI indicated if age <6 years or neurologic symptoms
• Hypothalamic hamartoma, optic glioma (NF-1), post-inflammatory, post-irradiation
• Treatment: GnRH agonists (leuprolide). Reversible
🩸 Peripheral Precocious Puberty (Gonadotropin-Independent)
• McCune-Albright syndrome: café-au-lait spots (coast of Maine), polyostotic fibrous dysplasia, ovarian cysts → estrogen production, vaginal bleeding often precedes breast development
• Ovarian follicular cyst: most common estrogen-secreting mass; may fluctuate in size
• Granulosa cell tumor: estrogen-producing ovarian tumor, palpable mass
• Exogenous estrogens: creams, lotions, oral contraceptives, meat contamination
📋 Other Causes
• CAH (21-hydroxylase deficiency): virilization (clitoromegaly, pubic hair), advanced bone age, increased 17-OHP
• Hypothyroidism (Van Wyk-Grumbach): delayed bone age (paradoxical), breast development, galactorrhea, treat with levothyroxine
• Premature thelarche: benign, normal growth, no progression; follow clinically
📌 Decision strategy: Bone age advanced (except hypothyroidism). GnRH stimulation test distinguishes central (pubertal LH) from peripheral (prepubertal LH). Always consider exogenous estrogen exposure.