BENIGN AND MALIGNANT PHYLLODES TUMORS - MAMMOGRAPHIC AND SONOGRAPHIC FINDINGS

PURPOSE: To characterize imaging findings that suggest the benign or m alignant histologic nature of phyllodes tumors. MATERIALS AND METHODS: Clinical and imaging findings were retrospectively reviewed in 46 wom en with 51 phyllodes tumors (32 benign, 19 malignant) identified at pr eoperative mammography. Thirty of these tumors were also evaluated wit h preoperative sonography. RESULTS: Mammography showed nonspiculated s oft-tissue masses in 49 tumors. Four masses contained calcifications; three of these masses were benign. The tumors were 1-20 cm in diameter ; tumors 3 cm or larger were statistically significantly more likely t o be malignant (P < .004). Sonography showed solid, hypoechoic masses in 28 cases. At sonography, cystic areas were more often seen in malig nant than in benign tumors, but the difference was not statistically s ignificant. CONCLUSION: There is substantial overlap in the imaging ch aracteristics of benign and malignant phyllodes tumors. A tumor diamet er of 3 cm or greater appears to be associated with a higher likelihoo d of malignancy.