Based on the symptoms presented, which diagnosis is most likely for a woman with prolonged, heavy menses and an enlarged uterus with firm masses?

The diagnosis of leiomyoma, commonly known as uterine fibroids, aligns well with the symptoms of prolonged and heavy menstrual bleeding (menorrhagia) alongside an enlarged uterus that presents with firm masses. Leiomyomas are benign smooth muscle tumors of the uterus that can cause significant changes to the uterine size and structure, leading to heavy menstrual bleeding and abdominal discomfort.

The characteristic firmness of the masses is a key indicator, as leiomyomas typically feel solid upon examination due to their muscle composition. Moreover, these fibroids can lead to distortion of the uterine cavity, contributing to abnormal bleeding patterns. The presence of an enlarged uterus combined with the description of tangible masses strongly suggests that leiomyomas are the underlying cause of the symptoms presented.

While adenomyosis, endometriosis, and endometrial polyps may also be associated with abnormal bleeding, they present with different clinical findings. Adenomyosis often involves an enlarged, tender uterus but may not present as distinctly firm masses. Endometriosis can cause painful menstruation but is not characterized by a markedly enlarged uterus with palpable masses. Endometrial polyps can contribute to menorrhagia as well but do not typically result in a significantly enlarged uterus. These distinctions further solidify