A 4-year-old girl presents with recurrent episodes of vaginal bleeding and breast development over 6 months. She has large irregular-bordered café-au-lait spots on her left trunk and left thigh. Radiograph shows polyostotic fibrous dysplasia of the left femur. LH and FSH are prepubertal, but estradiol is elevated at 45 pg/mL. GnRH stimulation shows no LH response. What is the diagnosis?
- A McCune-Albright syndrome ✓
- B Central precocious puberty
- C Ovarian granulosa cell tumor
- D Primary hypothyroidism with precocious puberty
Correct answer: A. McCune-Albright syndrome
Explanation
McCune-Albright syndrome is characterized by the triad of gonadotropin-independent precocious puberty, polyostotic fibrous dysplasia, and café-au-lait spots with irregular 'coast of Maine' borders. The prepubertal LH response to GnRH confirms peripheral (GnRH-independent) precocity, distinguishing it from central precocious puberty.
Reference: Nelson Textbook of Pediatrics, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.