The purpose of this chapter is to provide general guidelines on specimen evaluation and highlight some clinically relevant issues, which may help to increase the efficiency and overall quality of pathologic assessment.
As outlined in the protocol for the examination of breast specimens released by the College of American Pathologists,1 it is important that, together with the specimen, the pathologist receives specific information identifying the patient and the anatomic site from which the specimen was obtained, including its laterality and specific location in the breast (quadrant designation, subareolar location, etc), the date and type of procedure that was performed, and the name of the treating physician to whom the final report should be addressed.
In the course of gross examination, the prosector needs to state if the specimen was received in a fresh state or in fixative and specify the latter. Usually, a breast specimen consists of only 1 piece, but if more than 1 piece is present, the number should be stated, and the size of each piece measured in 3 dimensions. A specimen consisting of 3 or more pieces should not be inked. The gross description of the specimen needs to include any orientation markings identified on the specimen (see also "Margin Evaluation" later in the chapter). If a tumor is present, its size needs to be measured and reported. It is best to give the 3 dimensions of a tumor, but no definite consensus exists on this and the CAP recommends specifying the largest diameter.1 Description of the tumor also includes comments on its outline (eg, circumscribed, ill defined), characteristics of the cut surface (eg, bulging, retracted, papillary), consistency (eg, firm, soft, rubbery, friable, mucoid), and color (eg, white, tan, brown-red). The relation of the tumor to the surgical margin should also be clearly specified. Gross examination of a fresh specimen allows better appreciation for subtle differences in the characteristics of the tissue, and enhances both visual and tactile inspection. It also minimizes exposure to formalin fumes, although it does not protect from blood-borne pathogens.
Recently published ASCO/CAP guidelines have recommended optimal fixation times and choice of fixative for breast tissue samples, greatly contributing to protocol standardization.2 Poor or uneven tissue fixation negatively affects tissue preservation and immunohistochemical assessment. Proteolytic tissue degradation due to delayed fixation can result in weak or absent immunoreactivity and nonspecific binding of the antibody. Shorter than optimal formalin fixation (or attempts to fix large tissue pieces without proper sectioning) can result in a mixed fixation pattern where cross-linking occurs only at the periphery of the tissue and the center is either coagulatively fixed by alcohol or remains unfixed.3 Mixed fixation is a common cause of different staining intensities at the periphery and in the center of the same section, and can lead to difficulties in histologic diagnosis and misinterpretation of ER, PR, and HER2 results. Very long fixation should also be avoided as it may cause ...