Percutaneous Breast Biopsy: Local Tumor Spread, Ontogenetic Compartments, and Cell Transgression/Reverse Morphogenesis Theory.

Background Observing patients submitted to percutaneous biopsy at our service who had post-biopsy breast magnetic resonance imaging scans for breast carcinoma staging, we observed tumor extension through the biopsy tract in some lesions, compromising skin and subcutaneous tissue. This study aimed to evaluate tumor extension through the biopsy tract in patients diagnosed with breast carcinoma undergoing neoadjuvant chemotherapy with a radioactive seed marker to locate the original tumor area by retrospectively analyzing MRI, ultrasonography, and histological reports. Methods We evaluated tumor extension through a biopsy tract in consecutive patients included in a prospective observational study protocol to assess the applicability of radioactive seed localization before breast surgery. Sixty-two patients included in the radioactive seed protocol were retrospectively evaluated. The abnormal enhancement in the biopsy tract was assessed by magnetic resonance imaging scans performed for clinical staging and seed localization as proposed in the original study protocol, with complementary target ultrasonography of the findings and ultrasound-guided biopsy of the suspected lesion. Results Four of the 62 patients in the protocol had abnormal enhancement in the biopsy tract, and three patients had a positive biopsy for carcinoma in the tract. The lesions that showed extension along the tract were luminal A, luminal B, and luminal hybrid carcinomas, with an average diameter of 3.9 cm. Conclusions Our study has shown the possibility of tumor extension through the biopsy tract in patients undergoing diagnostic percutaneous breast biopsy for breast cancer. These findings are crucial for understanding the biopsy procedures' potential risks and clinical implications.