Final answer:
Adenocarcinoma of the vagina is most often caused by a sexually transmitted infection with human papillomavirus (HPV).
Step-by-step explanation:
Patients who typically have adenocarcinoma of the vagina are women with a history of HPV infection. Adenocarcinoma of the vagina is most often caused by a sexually transmitted infection with human papillomavirus (HPV). There are over 100 related viruses in the HPV family, and the characteristics of each strain determine the outcome of the infection. In all cases, the virus enters body cells and uses its own genetic material to take over the host cell's metabolic machinery and produce more virus particles.