These causes of hyperandrogenism are rare. The clinical presentation is often suggestive (see above, Diagnosis of Hyperandrogenism in Female Adolescents). The laboratory investigations will rapidly confirm the clinical suspicion and imaging techniques will localize the tumor (see same section above). Some extreme forms of PCOS, such as hyperthecosis, may also present with similar clinical and hormonal features. However, they are very infrequent in adolescents, unless the patient has an extreme insulin resistance (HAIR-AN syndrome), either genetic or secondary to a congenital or acquired portosystemic shunt.

Cushing Syndrome
Some adrenal tumors may secrete high amounts of androgens and cortisol. Therefore, the clinical presentation might be dominated by symptoms of glucocorticoid excess. Conversely, these symptoms may be mild in a hyperandrogenic adolescent patient with a pituitary Cushing disease. Therefore, it is wise to check the 24-hour urinary-free cortisol level in any doubtful situation, especially in obese patients with the full-blown PCOS.

Hyperprolactinemia
PRL excess stimulates the secretion of adrenal androgens, mainly DHEAS. Therefore, a mild hyperandrogenism frequently accompanies the clinical expression of a prolactinoma, but it is seldom the main complaint. Conversely, mild hyperprolactinemia frequently occurs in PCOS, but it has no specific expression and often disappears spontaneously.

Idiopathic Hirsutism
This diagnosis is one of exclusion. In particular, it requires that a nonclassic form of PCOS has been ruled out (see above, Classification of PCOS).
It is often observed in patients with a Mediterranean or Hispanic ethnic background.
It is thought to result from increased skin 5α-reductase activity.

Drugs
Drugs that are most commonly responsible for the development of virilizing effects include anabolic steroids, progestins, antiepileptic drugs, cortrosyn and metyrapone. In one study, a large majority of the patients receiving valproate had polycystic ovaries at ultrasounds or an elevated serum T concentration.

These abnormalities were more common when treatment had been started before the age of 20 years.

Hirsutism and androgenic alopecia must be differentiated from druginduced hypertrichosis or hair loss, which are independent from hormone stimulation.