What is the Most common cancer of the female genitourinary tract?
Leiomyoma, or fibroid, is the most common neoplasm of the female genitourinary tract, affecting up to 30% to 40% of women over the age of 35. Leiomyomas are benign smooth muscle tumors that are hormonally responsive, sometimes demonstrating dramatic growth during pregnancy, and are most often seen in the uterus, although they may also occur in other locations such as in the cervix or broad ligament. They may either be detected incidentally on imaging or may be associated with vaginal bleeding, pelvic pain, infertility, or a palpable abnormality. Leiomyomas may undergo various types of degeneration including hyaline (the most common), cystic, myxoid, red (hemorrhagic), or fatty degeneration (also called lipoleiomyoma).
On imaging, well-circumscribed myometrial masses are seen, which are more commonly multiple than solitary, may be homogeneous or heterogeneous in appearance, and typically exert mass effect upon adjacent structures such as the endometrium. On US, leiomyomas are usually hypoechoic but can be isoechoic or hyperechoic relative to the surrounding myometrium. Anechoic or hypoechoic cystic components may be detected, and calcifications, when present, will appear as echogenic foci with posterior acoustic shadowing. On CT, leiomyomas have soft tissue attenuation with variable degrees of enhancement, and foci of very high attenuation calcification may also be present. On MRI, nondegenerated leiomyomas typically have homogeneous intermediate T1-weighted and low T2-weighted signal intensity relative to normal myometrium. Cellular leiomyomas may have relatively increased T2-weighted signal intensity, whereas leiomyomas with hyaline degeneration have decreased T2-weighted signal intensity similar to nondegenerated leiomyomas. Areas of increased T1-weighted signal intensity may be seen with hemorrhagic or fatty degeneration, whereas loss of signal intensity will only occur with the latter on fat-suppressed T1-weighted images. Increased T2-weighted signal intensity components may be seen with cystic or myxoid degeneration, where the former does not enhance and the latter does enhance.