Development of the external genitalia: perspectives from the spotted hyena (Crocuta crocuta).

This review/research paper summarizes data on development of the external genitalia of the spotted hyena, a fascinating mammal noted for extreme masculinization of the female external genitalia. The female spotted hyena is the only extant mammal that mates and gives birth through a pendulous penis-like clitoris. Our studies indicate that early formation of the phallus in both males and females is independent of androgens; indeed the phallus forms before the fetal testes or ovaries are capable of synthesizing androgens.

Advice on the management of ambiguous genitalia to a young endocrinologist from experienced clinicians.

The birth of a child with ambiguous genitalia is a challenging and distressing event for the family and physician and one with life-long consequences. Most disorders of sexual differentiation (DSD) associated with ambiguous genitalia are the result either of inappropriate virilization of girls or incomplete virilization of boys. It is important to establish a diagnosis as soon as possible, for psychological, social, and medical reasons, particularly for recognizing accompanying life-threatening disorders such as the salt-losing form of congenital adrenal hyperplasia.

Reflections on future research in adolescent reproductive health.

A group of basic scientists, clinicians, clinical investigators, psychologists, patient advocacy groups, and representatives from professional societies and governmental agencies met at the National Institutes of Health in October, 2007 with the long-term goal of having the menstrual cycle accepted and understood as a marker of general health in adolescent girls. An equally important goal was to develop a research agenda for this area of investigation. This chapter comprises the highlights of discussions throughout that meeting, with an emphasis on ideas generated during a final session led by an internationally renowned physician-scientist, in which reports from four breakout groups were presented.