What is the most likely diagnosis for a patient experiencing irregular, heavy menses, with an examination revealing a normal cervix and smooth, regularly shaped uterus?

The symptoms described in the scenario, particularly the combination of irregular, heavy menses alongside a normal cervical examination and a smooth, regularly shaped uterus, align closely with the diagnosis of endometrial hyperplasia.

Endometrial hyperplasia refers to the abnormal proliferation of the endometrium, which can occur due to unopposed estrogen stimulation. This condition often presents with menstrual irregularities such as heavy or prolonged bleeding, which fits the patient's description of irregular, heavy menses. The examination findings of a normal cervix and a uterus that is smooth and regular further support this diagnosis, as endometrial hyperplasia does not typically alter the external contour of the uterus.

Other conditions listed may present with similar symptoms but have distinctive features that differentiate them from endometrial hyperplasia. For example, adenomyosis often presents with a globular or enlarged uterus upon examination due to the invasion of endometrial tissue into the myometrium. Cervical polyps may cause irregular bleeding but would typically be visible upon examination of the cervix. Uterine leiomyomas (fibroids) can cause heavy menstrual bleeding as well, but they usually result in a uterus that is irregular or has palpable masses on exam.

In summary, the combination of the