Breast Pathology

The first question a breast pathologist seeks to answer when reading a breast biopsy is whether cancer is present. But the information included in the pathology report goes far beyond the “yes” or “no” diagnosis. Even if the biopsy is benign, we need to ensure that the calcifications seen on imaging correlate with calcifications seen on the core biopsy pathology specimen. The earliest stage of breast cancer, called ductal carcinoma in situ (DCIS), is usually detected in this manner. Discordance between pathology and imaging is addressed by means of communication between the radiologist and pathologist in a radiology-pathology conference or by individual communication.

A pathology report always has a detailed visual morphologic description of the tumor. The initial biopsy report includes information on whether the cancer is confined within the ducts (in situ carcinoma) or has breached the duct wall and invaded into the adjacent stroma (invasive carcinoma). We provide intraoperative consultation on sentinel lymph nodes in the frozen section suite to detect metastases, which will then help the surgeon in planning patient management. Additional details will be studied and added to the pathological report after mastectomy and sentinel node biopsy to determine whether the cancer has metastasized or spread to any lymph nodes.

Tumor size, histologic grade, and lymph node status are prognostic indicators that provide valuable information about the likely clinical outcome. For example, a patient whose tumor is well-differentiated and has negative margins, i.e., has clear margins, has a better prognosis than a patient whose tumor is one that is poorly differentiated and is present at the margin.