Frozen Section and Imprint Cytology in Sentinel Lymph Node Biopsy for Breast Cancer

Abstract

Recent trends toward conservative surgery for breast cancer and increasing detection of smaller invasive malignancies have shifted the traditional surgical approach from mastectomy to lumpectomy, and from complete axillary lymph node dissection to sentinel lymph node biopsy to avoid extensive procedures in clinically node-negative women (1),(2). Debate continues over radioisotope physical characteristics and the type of dyes, as well as the optimal time of injection and the role of axillary dissection in locoregional disease control ((1),(3). However, sentinel lymph node biopsy is successful in 92% to 98% of breast cancer patients and is increasingly being used for staging and prognostication, although low-volume micrometastatic disease may be present in up to 15% of nonsentinel nodes when sentinel lymph node biopsy is negative ((4),(5). Controversy also exists concerning the extent of tissue sampling and the modality of pathological assessment for the most sensitive and accurate detection of metastatic disease ((1),(6). Although the diagnostic armamentarium of the pathologist is rapidly expanding due to recent advances in molecular techniques, in most laboratories intraoperative assessment of sentinel lymph node histology is routinely done by either frozen section or imprint cytology, with rare and selective use of cytokeratin immunohistochemistry in diagnostically equivocal cases ((7)–(10).