Current Concepts in the Imaging of Uterine Sarcomas

Uterine Smooth Muscle Tumors: An Overview

Uterine smooth muscle tumors are a heterogeneous group of mesenchymal neoplasms with multiple histologic variants and distinct biological behaviors. Pathologic classification (benign, uncertain malignant potential, malignant) relies on the evaluation of mitotic index, necrosis, and degree of cytologic atypia, with different thresholds based on each subtype. Immunohistochemistry and other ancillary studies may be necessary to establish the diagnosis in a subset of cases, given the morphologic overlap with other mesenchymal neoplasms, including low-grade and high-grade endometrial stromal tumors, inflammatory myofibroblastic tumors, and PEComa. Recent advances in molecular diagnostics have refined the classification of smooth muscle tumors, but most cases are diagnosed purely on histologic grounds.

Diagnostic Accuracy of Ultrasound in the Diagnosis of Uterine Leiomyomas and Sarcomas

BACKGROUND

Differential diagnosis between uterine leiomyomas and sarcomas is challenging. Ultrasound shows an uncertain role in the clinical practice given that pooled estimates about its diagnostic accuracy are lacking.

OBJECTIVES

To assess the accuracy of ultrasound in the differential diagnosis between uterine leiomyomas and sarcomas.

DATA SOURCES

A systematic review was performed searching 5 electronic databases (MEDLINE, Web of Sciences, Google Scholar, Scopus, and ClinicalTrial.gov) from their inception to June 2023.

METHODS OF STUDY SELECTION

All peer-reviewed observational or randomized clinical trials that reported an unbiased postoperative histologic diagnosis of uterine leiomyoma or uterine sarcoma that also comprised a preoperative ultrasonographic evaluation of the uterine mass.

TABULATION, INTEGRATION, AND RESULTS

Sensitivity, specificity, positive and negative likelihood ratios, diagnostic odds ratio, and area under the curve on summary receiver operating characteristic were calculated for each included study and as pooled estimate, with 95% confidence interval (CI); 972 women (694 with uterine leiomyomas and 278 with uterine sarcomas) were included. Ultrasound showed pooled sensitivity of 0.76 (95% CI, 0.70-0.81), specificity of 0.89 (95% CI, 0.87-0.92), positive and negative likelihood ratios of 6.65 (95% CI, 4.45-9.93) and 0.26 (95% CI, 0.07-1.0) respectively, diagnostic odds ratio of 23.06 (95% CI, 4.56-116.53), and area under the curve of 0.8925.

CONCLUSIONS

Ultrasound seems to have only a moderate diagnostic accuracy in the differential diagnosis between uterine leiomyomas and sarcomas, with a lower sensitivity than specificity.