Malignant seeding following percutaneous breast biopsy: documentation with comprehensive imaging and clinical...

The aim of this study was to demonstrate convincing evidence that percutaneous breast biopsy may result in displacement of malignant cells that can initiate tumor growth at a separate anatomic site, other than the index lesion. Two patients with malignancy diagnosed by percutaneous breast biopsy were followed up with subsequent imaging. The observation of displaced cells initiating subsequent malignant growth was compared retrospectively with the previous year's outcomes following percutaneous breast biopsy. Two cases of displaced malignant cells resulting in malignant growth at a separate site along the biopsy needle track were demonstrated by imaging. During the preceding year, 1644 biopsies with 298 malignant results were compared with the outcomes of these two patients, resulting in a 0.7% incidence of malignant seeding. No identifiable factors could be identified to predict under what conditions this iatrogenic complication occurs. Although uncommon, percutaneous breast biopsy can result in malignant seeding, and raises issues regarding informed consent and proper subsequent treatment.