Risks of Being Malignant or High Risk and Their Characteristics in Breast Lesions 20 mm or Larger After Benign Results on Ultrasonography-Guided 14-Gauge Core Needle Biopsy.

Abstract

PURPOSE: The malignancy risk, risk of being high-risk lesions after benign results on ultrasonography-guided 14-gauge core needle biopsies (US-CNBs), and their characteristics in breast lesions of 20 mm or greater were investigated. METHODS: Eight hundred forty-seven breast lesions with benign results on US-CNB were classified as benign, high risk, and malignant through excision and clinical follow-up. The risks of being malignant or high risk were analyzed in all lesions, lesions 20 to 29 mm, and lesions 30 mm or greater. Their clinicopathological characteristics were evaluated. RESULTS: Of 847, 18 (2.1%) were malignant, 53 (6.3%) were high-risk lesions, and 776 (91.6%) were benign. Of 18 malignancies, 6 (33.3%) were malignant phyllodes tumors and 12 (66.7%) were carcinomas. In benign lesions 20 to 29 mm, risks of being malignant or high risk were 1.6% (9 of 566) and 4.4% (25 of 566). In 281 lesions 30 mm or greater, the risks of being malignant or high risk were 3.2% and 10%. The risk of being high risk in lesions 30 mm or greater was 10%, significantly higher than 4.4% of lesions 20 to 29 mm (P = 0.002). CONCLUSIONS: Excision can be considered in lesions measuring 20 mm or larger because of the 2.1% malignancy risk and the 6.3% risk of being high-risk lesions despite benign results on US-CNB. Excision should be considered in lesions measuring 30 mm or larger because of the 3.2% malignancy risk and the 10% risk of being high-risk lesions.