Percutaneous core needle biopsies comprise the most common type of breast specimens in current practice. The indications for such biopsies include palpable and nonpalpable breast lesions. The majority of these biopsies are performed with the aid of imaging modalities, such as mammogram, ultrasound, or MRI (Figs. 5.1 and 5.2). The operator is usually a breast radiologist or a surgeon. Neither sample adequacy check nor diagnostic evaluation is requested on such samples. However, documentation of certain pertinent information at the time of gross examination is critical for the reasons provided below. It is therefore important that the handling of this sample is discussed separately in this book.