Phyllodes Tumor of the Breast: Ultrasound-Pathology Correlation

Objective: The purpose of this study is to evaluate the sonographic and histopathologic features distinguishing benign from borderline and malignant phyllodes tumors.

Materials and methods: The ultrasound examinations of women with pathologically proven phyllodes tumors from 2004 to 2011 were retrospectively reviewed. The sonographic features of benign, borderline, and malignant phyllodes tumors were compared and analyzed using the American College of Radiology's BI-RADS ultrasound lexicon. Fisher exact test and Wilcoxon rank sum test were used for statistical analysis.

Results: Fifty-nine women were included in the study; 28 benign (47%), 19 malignant (32%), and 12 borderline (20%) phyllodes tumors were identified. Significant univariate predictors of increased risk of borderline or malignant phyllodes tumors were patient age greater than 55 years (p = 0.014), irregular lesion shape (p = 0.011), and longest lesion dimension greater than 7 cm (p = 0.0022) at sonography. No significant differences were observed in lesion margins, boundaries, echo patterns, or posterior acoustic features.

Conclusion: There is substantial overlap in the sonographic features of benign and borderline or malignant phyllodes tumors. Understanding the clinical and sonographic features of phyllodes tumors may aid the radiologist in predicting biological behavior, including the likelihood of benign versus borderline or malignant phyllodes tumors at pathologic analysis.