The middle-aged patient with long dark hair made it very clear that this was not her first urinary tract infection. "It's because when I urinate," she said, "I need to use a catheter." "Just ask one of the older nurses or doctors," she said, smiling. "They all know me." But as I would learn, it was not because of her recurrent infections that so many of my colleagues knew her. Several years earlier, she had come in for a routine operation. The doctor had evaluated her before the operation, learned that she was a homemaker and met her husband. But on the morning of her operation, as he pulled down the sheets to begin inserting the urinary catheter into his now sleeping patient, he was startled to discover that the patient was not exactly who he had assumed she was. She was transgender, and where he had been expecting to find female genitalia, he found male genitals instead.