In adenomyosis, endometrial glandular and stromal cells grow inside the myometrium, and form localized or diffusely expanding islets. Smooth muscle cells of the uterus surrounding the adenomyosis colonies become hypertrophic, which may lead to abnormal contractions of the uterine wall. Adenomyosis is an estrogen-dependent disease with abnormal uterine bleeding and dysmenorrhea as typical symptoms. The disease may even be asymptomate. The diagnosis is made by histologically or ultrasonic or MRI imaging. Adenomyosis can be treated with hormonal medications. Fertility-sparing radiologic and surgical techniques are also available.