A Case of a Transwoman with Colorectal Cancer after Flap Vaginoplasty

Vaginoplasty is a gender-affirming surgery (GAS) for transwomen that laid its foundation in the 1950s and continues to be widely practiced worldwide. We present here a case of a 70-year-old transwoman who underwent lower anterior resection for rectal cancer 12 years after vaginoplasty. The preoperative diagnosis was rectal cancer (Rb-Ra, type 2, cT2N0M0, stage 1). All imaging studies showed a cord-like structure between the prostate and the anterior wall of the rectum, which was thought to be the neovagina. Careful dissection of the anterior rectal wall was required because the distance between the neovagina and the rectum was only 1.5 mm. The role of hormonal therapy and GAS in cancer development in transwomen is unclear. It is important to have regular check-ups for malignancies in patients who have undergone GAS, and if surgical procedures are needed, they should be treated by physicians who are familiar with the procedure.