Ultrasound differentiation of benign versus malignant solid breast masses

Objective: To determine the reliability of ultrasonographic features in differentiating benign from malignant solid breast masses. Design: Descriptive, analytical study. Place and Duration of Study: Radiology Department, Aga Khan University Hospital, Karachi from July 2000 to June 2002. Subjects and Methods: One hundred solid breast masses in females with a tissue diagnosis available were reviewed. Two radiologists reviewed the sonographic features of masses without knowledge of clinical history or histologic examination results. Ultrasound features were corrected later with histologic features to determine the reliability of the former in benign or malignant nature of nodules. Results: Ultrasound features that most reliably characterize masses as benign were a round or oval shape, circumscribed margins and a width to antero-posterior (AP) dimension ratio greater than 1.4. Features that characterized masses as malignant included irregular shape, spiculated margins and width to antero-posterior (AP) dimension ratio of 1.4 or less. If these three most reliable criteria had been strictly applied by the primary reporting radiologist, the overall cancer biopsy yield would have increased. Conclusion: The data confirms that certain ultrasound features can help differentiate benign from malignant masses. However, practice and interpreter variability should be further explored before these criteria are applied to defer biopsy of solid masses.