Abstract:

Objective  To Compare the positive detection rates of hematoxylin and eosin stain with immunohistochemical stain by semi-consecutive sectioning of  histopathologically negative cervical lymph nodes from laryngeal or laryngopharyngeal squamous cell carcinoma.The  relationship between micrometastasis and clinicopathological factors,  micrometastasis and early recurrences was studied primitively. Methods  Totally, 326 negative cervical lymph nodes (CLNs) from 13 patients (15 sides), with laryngeal or laryngopharyngeal squamous cell carcinoma, were included in this study. Two methods( H&E stain and EnVison′s two-step IHC technique with monoclonal antibody CK (AE1/ AE3)) combined with semi--consecutive sectioning(per-50μm) were applied to detect the micrometestasis . The positive detection rates of H&E and IHC were compared by Chisquare test . The clinicopathological factors, consisted of sex, age, pT stage, clinical typing, grade of differentiation,depth of primary tumor invasion, were studied and all the cases were followed-up for 11～56 months（median time 31.4 months）. Further, the relationship between micrometastasis and clinicopathological factors, micrometastasis and early recurrences were analyzed with Chisquare test.  Results  1. All the paraffin specimens of 75 cases were semi-consecutively sectioned into two sets of 750 slices for H&E stain and IHC stain. In the IHC group, 40（5.33%）slices were found positive in 7 (2.14 %) lymph nodes which came from 5(38.46 %) patients Howerver, only 24（3.20%）positive slices were found in 3 lymph nodes of 2 patients in the H&E group.The positive detection rates of these two groups were statistically significant（Ρ<0.05）. 2. There was no statistically significance between micrometastasis and the clinicopathological factors (Ρ>0.05) except for the age (Ρ=0.032). There was no statistically significance between micrometastasis and early recurrences. Conclusion  1. Even the experienced pathologists may miss the micrometastasis in cervical lymph nodes from laryngeal or laryngopharyngeal carcinoma if only by H&E stain,though  semi-serial or serial section was applied in those cases.While the IHC technique can obviously increace the positive detection rates. 2.The possible relationship between micrometastasis and clinicopathological factors, micrometastasis and recurrences should be verified with more samples and long-term follow-up.

Key words: Laryngeal carcinoma； Laryngopharyngeal carcinoma； Micrometastasis； Immunohistochemical technique； Cytokeratin