Diagnostic Approach to Suspected Leiomyoma

Imaging Modalities

The American College of Radiology recommends using MRI with gadolinium-based contrast as the preferred imaging modality for evaluating potential malignancy in suspected leiomyomas, with sensitivity and specificity up to 100% and 100% respectively for leiomyosarcomas 1
Color Doppler evaluation can identify vessels within lesions, but cannot definitively differentiate between benign and malignant conditions, as stated by the Journal of the American College of Radiology 1, 2
Diffusion-weighted MRI sequences can help differentiate leiomyosarcoma from benign leiomyoma and should be strongly considered, according to the American College of Radiology 1, 3, 4

The American College of Radiology suggests performing transvaginal and transabdominal ultrasound with Doppler as the initial evaluation for suspected leiomyoma, and proceeding to MRI with contrast and diffusion-weighted sequences if ultrasound findings are suspicious or inconclusive 1, 3, 4
The Society of Radiologists in Ultrasound recommends not relying on CT for distinguishing benign from malignant uterine masses, due to its limited diagnostic value 1

Rapid fibroid growth with tenderness in postmenopausal women should raise suspicion for leiomyosarcoma and warrants urgent referral, as recommended by the American College of Obstetricians and Gynecologists 3
Clinical suspicion for malignancy should not be attributed to imaging alone, and tissue diagnosis may be necessary, as stated by the American College of Radiology 1, 2