What is a common presentation in Classic Simple Congenital Adrenal Hyperplasia?

In Classic Simple Congenital Adrenal Hyperplasia (CAH), specifically the most common form known as 21-hydroxylase deficiency, an excess of androgens (male hormones) occurs due to the adrenal glands' inability to produce adequate cortisol. This hormonal imbalance significantly impacts the development of external genitalia, particularly in genetically female individuals (46,XX).

As a result, one of the hallmark presentations of Classic CAH is the development of androgynous genitalia. This can present as ambiguous genitalia, where the external genital characteristics do not clearly align with typical male or female anatomy. In severe cases, this can manifest as enlarged clitorises or partially fused labia that may resemble a scrotum.

Therefore, the presentation of androgynous genitalia is a quintessential feature of Classic Simple CAH, especially when diagnosed at birth or shortly afterward. Other options such as severe renal abnormalities, complete female phenotype, and short stature may occur in relation to the condition but are not defining characteristics of Classic CAH. The focus is predominantly on the virilized characteristics that arise due to the hormonal excess, making androgynous genitalia the most recognizable and relevant presentation in this context.