A Transgender Woman with Testicular Cancer: A New Twist on an Old Problem.

We present the case of a transgender woman who developed rising testosterone and estradiol levels while on feminizing hormones. After months of uncertainty about the cause of her elevated hormone levels, her physician found a large testicular mass on examination. The patient was diagnosed with a rare virilizing form of testicular cancer. We review the biopsychosocial factors that led to a delay in diagnosis, appropriate screening for patients whose anatomical parts are incongruent with their gender identity, and the difficulty of learning to become a competent provider for transgender patients at a time when resources and educational opportunities are lacking.