A 5-year-old girl is brought to the office for evaluation of pubic hair. Her mother noticed dark hair under the girl's arms and in her pubic area several days ago when helping her bathe. The patient has no headaches, visual changes, abdominal pain, or behavioral changes. She is obese and currently on a diet and exercise program. Several maternal relatives have type 2 diabetes mellitus. The patient's height has been tracking along the 50th percentile and weight at the 97th percentile. Physical examination shows a cooperative girl with mild facial acne. No breast buds are palpable. She has dark, coarse hair across the pubis and under both axillae. External genitalia appear normal. Bone age is normal. Which of the following is the most likely diagnosis for this patient?
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Development of secondary sexual characteristics is premature (ie, precocious) in girls age <8 and boys age <9. Obese children are at high risk for precocious development as adiposity can trigger excess insulin production, which then stimulates the adrenal glands to produce sex hormones.
Isolated premature adrenarche is caused by early activation of adrenal androgens. Typical manifestations include body odor, oily skin, acne, and pubic and axillary hair. However, estrogen and testosterone levels remain normal; therefore, there are no other signs of premature puberty (eg, breast development, testicular enlargement) or virilization (eg, clitoromegaly). Mildly elevated dehydroepiandrosterone sulfate present in children with premature adrenarche is not sufficient to affect skeletal growth; therefore, bone age is normal in these patients.
Isolated premature adrenarche is generally benign but a risk factor for developing polycystic ovary syndrome, type 2 diabetes mellitus, and metabolic syndrome, especially in obese patients.
(Choice A) Girls with classic congenital adrenal hyperplasia (CAH) present in infancy with salt-wasting and virilization. Due to partial 21-hydroxylase deficiency, nonclassic (late-onset) CAH manifests in childhood with premature pubarche/adrenarche (without virilization). However, significant elevations in androgen levels associated with CAH accelerate skeletal maturity, and an advanced bone age is expected.
(Choice B) Granulosa cell estrogen/progesterone-secreting tumors typically present in middle-aged women with an ovarian mass and menstrual abnormalities. In rare cases, children with this tumor may have premature breast development and menses due to hyperestrogenism, but not isolated acne and pubic hair.
(Choice C) Malignant testosterone-secreting hepatoblastomas are a rare cause of premature adrenarche and occur almost exclusively in boys.
(Choices D, E, and G) Hypothalamic glioma, pituitary hamartoma, and idiopathic precocious puberty are causes of central precocious puberty, which is characterized by advanced bone age, elevated FSH and LH, and true precocious development (eg, breast development).
(Choice F) McCune-Albright syndrome is characterized by peripheral precocious puberty, irregular café-au-lait macules, and fibrous dysplasia of the bone. Girls typically have premature vaginal bleeding and breast development, which are not seen in this child.
Educational objective:
Premature adrenarche is caused by early activation of adrenal androgens and is more common in obese children. Typical presentation includes precocious development of pubic and axillary hair, acne, and body odor in a child with a normal bone age.