Myometriosis is a rare condition characterized by the presence of endometrial-like tissue within the myometrium, the muscular layer of the uterus. This can lead to symptoms similar to endometriosis, including pelvic pain, heavy menstrual bleeding, and infertility. Diagnosis often involves imaging techniques like MRI or ultrasound, and treatment may include medications, hormonal therapies, or surgical interventions. It is distinct from endometriosis, which primarily affects the pelvic cavity outside the uterus.