THU197 Peripheral Precocious Puberty In A 6-year-old Girl With Extreme Estradiol Elevation With Rapid Normalization: A Case Report

Disclosure: L. Meller: None. M. Marinkovic: None. M.E. Patterson: None. Background: Peripheral precocious puberty (PPP) in girls is typically associated with ovarian or adrenal tumors, ovarian cysts, McCune-Albright syndrome (MAS), or exogenous hormone exposure. We present an unusual case of PPP with extreme estradiol elevation and rapid normalization. Clinical Case: A 6.5-year-old previously healthy girl presented with two-month history of bilateral breast growth and tenderness, associated with daily cramping. Subsequently, she developed clear, odorless vaginal discharge. Two days prior to the visit she started light vaginal bleeding. Parents denied any medication intake or use of lavender or essential oils. She had no family history of early puberty. On the exam, she was tall for her age (95%) with a recent growth spurt. She had breast buds (Tanner 2) and vaginal bleeding without pubic hair (Tanner 1) or signs of hyperandrogenemia. There were no skin lesions or gross bone abnormalities. Bone age was equal to chronological age. She had an extreme elevation of estradiol of 156pg/mL and 170pg/mL (reference range<=16pg/mL) measured two weeks apart with prepubertal LH/FSH. Thyroid tests were normal. Pelvic ultrasound and abdomen/pelvis CT showed no abnormalities of ovaries and adrenal glands. Nine days after the onset, vaginal bleeding and cramping spontaneously resolved. Estradiol levels measured two days after cessation of vaginal bleeding normalized (7pg/mL) while LH/FSH remained prepubertal. Interestingly, two weeks after the bleeding stopped her pelvic ultrasound showed significantly enlarged ovaries (R 4.1mL, L 4.3mL), while her estradiol remained normal (5pg/mL). Conclusion: We describe an unusual presentation of PPP in a young girl with extreme estradiol elevation causing simultaneous premature breast development and vaginal bleeding. We suspect PPP was secondary to ruptured ovarian cyst that was not captured by imaging. Other differentials include MAS, exogenous hormone exposure, adrenal or ovarian tumors. These were unlikely due to lack of abnormal skin or bone findings, environmental hormone exposure and normal imaging. Her ovarian enlargement could be secondary to high endogenous estrogen exposure, and she may be at risk of developing central precocious puberty. This unique case emphasizes the importance of prompt assessment of children with precocious puberty and discusses the differential diagnosis process for PPP with markedly elevated estradiol with rapid normalization. Presentation: Thursday, June 15, 2023