Are fine-needle aspiration biopsy-derived cell blocks a useful surrogate for tissue samples in breast cancer?

Aims: The diagnosis of breast cancer (BC) is based on clinical examination in combination with imaging, and confirmed by pathological assessment of core needle biopsy or fine-needle aspiration biopsy (FNAB). The biological profile of the lesion is needed to define the prognosis and establish therapy. Given the importance of an early and minimally invasive diagnosis, we aimed to verify whether the biological features detected in FNAB-derived cytological material reflect the biological characteristics of surgical samples.