Patients with pending breast biopsies will have the tumor site's tissue dielectric constant (TDC) measured prior to the biopsy. Similar TDC measurements will be made at a standard breast site on the biopsied breast and on mirrored sites on the non-affected breast.

Patients with pending breast biopsies will have the tumor site's tissue dielectric constant (TDC) measured prior to the biopsy. Similar TDC measurements will be made at a standard breast site on the biopsied breast and on mirrored sites on the non-affected breast. Values obtained at the biopsy site will be compared against the outcome of the biopsy analysis: benign vs. malignant. In addition the measurements obtained at the standardized site for all breasts will be used to establish a set of reference values to characterize breast TDC values. In addition, inter-breast differentials will be used to characterize these ranges for future studies and clinical assessments.

Inclusion Criteria:

• You must be scheduled for a breast biopsy of a breast mass or abnormality with the collaborating centers

Exclusion Criteria:

• You have any open wounds over the breasts
• You have had breast cancer
• You have or have had breast implants or have undergone any breast surgery or breast biopsy
• You have any implantable wires, this includes a Pacemaker, Implantable Cardioverter ° Defibrillators (ICDs), and/or Left Ventricular Assist Device (LVAD)
• You are pregnant

Must be scheduled for a breast biopsy with the collaborating centers

Measurements are made prior to the biopsy determination of whether tumor is benign or malignant