Sonographic Features of Breast Fibroepithelial Masses: Distinguishing Fibroadenoma from Phyllodes Tumour

Objective: Fibroepithelial tumours of the breast, which include fibroadenoma (FA) and phyllodes tumour (PT), are benign entities. Although they show different biological behaviours, distinguishing between them using imaging features or core needle biopsy (CNB) is challenging. We evaluated sonographic and CNB features, that could be useful for distinguishing between the two. Methods: A total of 121 patients with 125 lesions diagnosed as fibroepithelial tumours on ultrasound-guided CNB from March 2017 to April 2020 were studied. Among them, sonographic features of 68 lesions were retrospectively analysed. Clinicopathological results of CNB and surgical excision were reviewed using electronic medical records. Results: On ultrasound, tumour size, echogenicity, presence of an internal cleft, vascularity, and elasticity revealed significant differences between FA and PT. Tumour size >= 3 cm, presence of an internal cleft, and hard elasticity were common sonographic features in PTs. CNB revealed similar pathological results with surgical excision performed in 61 cases of 68 cases (89%). Conclusion: Ultrasonographic features can be useful imaging factors for distinguishing between FA and PT. Ultrasound-guided CNB can replace surgical excision with a high diagnostic accuracy in some cases.