Clinicians should be able to recognize common disorders of the male external genitalia, differentiate urgent from more benign conditions, perform initial diagnostic studies when indicated, treat appropriately, and refer to a specialist when necessary.

After completing this article, readers should be able to:

Male genital differentiation begins with the Y chromosome. During normal development, the sex-determining region Y chromosome (SRY gene) codes the bipotent gonad to undergo a male phenotype. (1) The origins of the testis can be traced back to the 5th week of gestation with formation of the gonadal ridge, an area where primordial germ cells migrate before differentiating. (1) The testicle is composed of both Leydig and Sertoli cells. The SRY gene helps drive differentiation of Sertoli cells that produce Mullerian inhibiting substance, also known as anti-Mullerian hormone, which prevents female pattern development. The Leydig cells, when stimulated by placental gonadotropin, also known...

You do not currently have access to this content.