Introduction/Background The recognition of uterine sarcoma allows correct therapy planning and choice of surgical approach. To help to distinguish benign myoma from sarcoma, we assessed the value of 6 sonographic criteria (Sarcoma Prediction Score – SPS) in a prospective cohort of consecutive patients with uterine masses.

Methodology Patients planned for surgery between 2015–2019 for presumed myometrial masses were prospectively evaluated with a standardized ultrasound examination. For triage, the following criteria were investigated: rapid growth i(3 months), high blood flow, atypical growth (postmenopause), irregular lining, central necrosis, and oval solitary lesion. The evaluation of the criteria was binary, the score could range from 0 to 6. Gold standard was histological diagnosis.

Results 522 myomas, 14 uterine sarcomas, 2 gastrointestinal stromal tumors in connection to the uterus, and 7 other malignancies were included. In the group of malignant tumors, 75.0% of patients were postmenopausal 25.0% premenopausal, while in the myoma group, 76.8% patients were premenopausal. The median SPS for mesenchymal tumors was 2.5 (range: 0–4, mean 2.6) vs 0 for myomas (range: 0–3, mean 0.17). The most common sonographic criteria leading to a false positive score in myomas were rapid growth and high blood flow. For the detection of sarcoma/mesenchymal tumors, at a threshold of >1, sensitivity was 93.75%, specificity 97.9%, PPV and NPV 57.7% and 99.8%, respectively. The AUC was 0.95.

Conclusion The use of the SPS could help to distinguish between myomas and sarcomas, with a high probability of benign histology if the score is negative. A higher risk of malignancy is given when ≥ 1 criteria are present in postmenopausal women. For premenopausal women, rapid growth and high blood flow may lead to false positive scores; a score ≥ 2 increases accuracy. We suggest the use of the SPS in the triage of patients with suspected myometrial lesions.