The value of step-sectioning in the diagnosis of lymph node micrometastasis in breast cancer

Objectives: Routine practice is to examine one histological section for evaluating secondary tumor deposits in the axillary lymph nodes in patients with breast cancer. The aim of the present study is to evaluate whether multiple levels of histological section detect significantly more metastatic deposits in axillary lymph nodes from breast cancer resection specimen than the standard practice of examining one section. Methods: A retrospective study of 30 patients with node negative breast cancer was performed whose specimens were received at AL-Jamhuri Teaching Hospital and private laboratories in Mosul city between the years 2008 and 2010. The original slides and the paraffin wax blocks containing the lymph nodes were retrieved from the archive, and 4 extra levels (separated by 30 μm) were cut from each block and were stained with H & E stain. Results: Of the 30 cases with node negative breast carcinoma, 4 (13.3%) were found to contain extra tumor deposits at deeper levels that were not detected at the original sections. Conclusion: Multiple levels of histological sections separated by relatively small intervals detect more tumor deposits in the axillary lymph nodes than the current practice of examining a single section.