The role of androgens in clitorophallus development and possible applications to transgender patients.

Abstract

The clitorophallus, or glans, is a critical structure in sexual development and plays an important role in how gender is conceptualized across the life span. This can be seen in both the evaluation and treatment of intersex individuals and the use of gender-affirming masculinizing therapies to help those born with a clitoris (small clitorophallus with separate urethra) enlarge or alter the function of that structure. To review the role of testosterone in clitorophallus development from embryo to adulthood, including how exogenous testosterone is used to stimulate clitorophallus enlargement in masculinizing gender-affirming therapy. Relevant English-language literature was identified and evaluated for data regarding clitorophallus development in endosex and intersex individuals and the utilization of hormonal and surgical masculinizing therapies on the clitorophallus. Studies included evaluated the spectrum of terms regarding the clitorophallus (genital tubercle, clitoris, micropenis, penis). Endogenous testosterone, and its more active metabolite dihydrotestosterone, plays an important role in the development of the genital tubercle into theclitorophallus, primarily during the prenatal and early postnatal periods and then again during puberty. Androgens contributeto not only growth but also the inclusion of a urethra on the ventral aspect. Exogenous testosterone can be used to enlarge the small clitorophallus (clitoris or micropenis) as part of both intersex and gender-affirming care (in transmasculine patients, up to 2cm of additional growth).Where testosterone is insufficient to provide the degree of masculinization desired, surgical options including phalloplasty and metoidioplasty are available. Endogenous testosterone plays an important role in clitorophallus development, and there are circumstances where exogenous testosterone may be useful for masculinization. Surgical options may also help some patients reach their personal goals. As masculinizing gender-affirming care advances, the options available for clitorophallus modifications will likely continue to expand and improve.