A 25-year-old female experiences constant premenstrual pelvic pain. What is the most likely diagnosis?

The diagnosis of endometriosis is supported by the symptom of constant premenstrual pelvic pain, which is characteristic of this condition. Endometriosis involves the growth of endometrial-like tissue outside the uterus, which can lead to significant inflammation and pain, particularly during the menstrual cycle. Women with endometriosis often experience chronic pelvic pain that worsens in the days leading up to menstruation due to the cyclical nature of hormonal changes, which affect the endometrial-like tissue.

In addition to pelvic pain, symptoms such as dysmenorrhea (painful periods), dyspareunia (pain during intercourse), and infertility may also be present in individuals with endometriosis. The pain is typically associated with menstrual cycles, providing a strong correlation with the patient's described symptoms.

While uterine leiomyomas (fibroids) can cause pelvic pain, they often present with heavy menstrual bleeding or pressure symptoms rather than constant pelvic pain preceding menstruation. Endometrial polyps are generally benign growths within the uterine lining and may cause abnormal bleeding but are less likely to be the sole cause of severe pelvic pain related to the menstrual cycle. Ovarian cysts can produce pelvic pain as well; however, they typically do not cause the same