Traditionally, if the clinical diagnosis is cancer, fresh breast tissue is submitted for frozen section examination before immediate mastectomy. Although this is still true, many breast biopsies are currently performed as outpatient procedures in the setting of an abnormal mammogram or a vaguely palpable abnormality. Frequently the lesion is small (less than 1.0 cm.) or is not grossly visible. The appropriate pathologic examination of breast biopsy material is determined by whether it is a mass or only a cluster of calcifications seen on a mammogram. Each breast biopsy specimen must be handled in a manner that will maximize the opportunity to arrive at the correct histologic diagnosis. In many instances, this means that a frozen section examination is contraindicated.