Immunohistochemistry of whole-organ sections of advanced human laryngeal cancer

Whole-mount sections have been in the interest of laryngologists for long time. The aim of this study was to demonstrate the technical aspects of processing horizontal whole-mount sections of advanced laryngeal cancer specimens after total laryngectomy. Those sections may provide new insights in the biology of laryngeal cancer. Six excised human larynges were block-embedded in paraffine. Serial sections were obtained as thin as 9 μm. Sections were stained by Giemsa and standard immunohistochemistry protocols with commercial antibodies against Cytokeratine5/6, Ki-67, Topoisomerase IIα, and p53. Four high-power fields were selected randomly in each section of a surface grid and the percentage of positive tumor cells was noted for each antibody in the respective field. Morphometric surface maps of protein expression were generated for each parameter. The tissues remained intact without major artifacts. Specific characteristics of the tumors were identified after evaluation of the whole-mount sections. Staining of cytokeratine was homogenous, whereas nuclear markers showed a distinct heterogeneity in the respective staining patterns. By analyzation of color-coded fusion images the spatial expression of the respective antibodies could be visualized.