The usefulness of cytokeratin immunohistochemistry in detection of lymph node micrometastasis in neck dissection specimens

Our study was designed to find out the rate and the characteristics of micrometastasis in cervical lymph nodes using immunohistochemical staining. From 69 patients, 1710 lymph nodes negative for metastasis on hematoxylin-eosin stain, were examined. Immunohistochemical stain was performed using pan-cytokeratin AE1/AE3 antibody. In 13 cases, occult lymph node metastasis was detected by immunohistochemical method. On retrospective review of the hematoxylin-eosin stain by the pathologist, lymph node metastasis was detected in 4 of 13 patients. Because the immunohistochemical method enhanced the detection rate of occult micrometastasis in cervical lymph nodes of head and neck squamous cell carcinoma patients, it may be recommended for routine diagnostic use in patient with negative for a lymph node metastasis on routine hematoxylin-eosin stain.