Uterine leiomyomas or uterine fibroids are the most common gynaecological tumours and occur in about 20-50% of women around the world. Ultrasonography (USG) is the first-line imaging examination in suspected fibroids and shows high sensitivity and specificity in diagnosing this condition. Ultrasound scans can be performed transvaginally (transvaginal scan – TVS) or transabdominally (transabdominal scan – TAS); both scans have advantages and limitations, but, in general, transvaginal sonography is superior to transabdominal sonography in most cases of pelvic pathology. Whether a leiomyoma is symptomatic or not depends primarily on its size and location. During ultrasound examination, leiomyomas usually appear as well-defined, solid, concentric, hypoechoic masses that cause a variable amount of acoustic shadowing. During the examination of leiomyomas differential diagnosis is important. Some of the most common misdiagnosed pathologies are adenomyosis, solid tumours of adnexa, and endometrial polyps.
The following table describes the differentiating features between fibroid and adenomyosis.
Feature Typical fibroid Adenomyosis
Serosal contour of uterus Lobulated or regular Often globally enlarged uterus
Definition of lesion Well‐defined Ill‐defined in diffuse adenomyosis (adenomyoma may be well‐defined)
Symmetry of uterine walls Asymmetrical in presence of well‐defined lesion(s) Myometrial anteroposterior asymmetry
Outline Well‐defined Ill‐defined
Shape Round, oval, lobulated Ill‐defined
Contour Smooth Irregular or ill‐defined
Rim Hypo‐ or hyperechogenic No rim
Shadowing Edge shadows, internal shadows (often fan‐shaped shadowing) No edge shadows, fan‐shaped shadowing67