A 38-year-old nulliparous patient presents with complaints o…

A 38-year-old nulliparous patient presents with complaints of menorrhagia and pelvic pain that has worsened over the last 6 months in addition to constipation. Abdominal exam reveals a palpable, firm mass in the lower abdomen and a pelvic exam confirms an enlarged, irregularly shaped uterus. Which of the following would describe the pathophysiology of what this patient is experiencing?