Beyond size: the role of growth rate in managing adolescent breast masses.

INTRODUCTION: Adolescent breast masses are predominantly benign. Yet, distinguishing lesions that require intervention is critical. Current American Pediatric Surgical Association guidelines provide limited guidance for the management of masses <5 cm. The goal of this study was to develop a data-driven clinical management guideline for small adolescent breast masses. METHODS: Growth dynamics were assessed in a retrospective cohort of female patients ≤21 years with breast masses using serial measurements, and risk-optimized growth threshold was derived using Youden's J statistic. RESULTS: 344 patients (median 19.6 years [IQR, 17.8-20.9]) with 435 breast masses were included. Most masses (430 [98.8%]) were <5 cm. Overall, 56 masses (12.8%) required intervention, including 3 malignancies (0.6%) and 53 hypercellular lesions (12.2%). A growth rate threshold >22.5%/3 months distinguished hypercellular from non-hypercellular lesions. CONCLUSIONS: Among adolescent breast masses <5 cm, a growth rate threshold of 22.5%/3 months can be used for risk stratification and to guide selective intervention.