Polypoid squamous cell carcinoma of the larynx. An immunohistochemical study for ras p21 and cytokeratin

Abstract

Polypoid squamous cell carcinoma of the larynx consists of two components, namely, squamous cell carcinoma and sarcomatoid spindle cells. To further investigate the histogenesis of the spindle cell component, we studied two cases of polypoid squamous cell carcinoma of the larynx by immunohistochemistry and ultrastructural analysis. Positive staining for ras oncogene p21 and cytokeratin was demonstrated in both squamous cell carcinoma and spindle cell component. Only the latter component was positive for vimentin. Electron microscopic examination showed well-developed desmosomes in spindle cells. These results suggest that the spindle cell component is epithelial in origin and malignantly neoplastic; it originates from mesenchymal metaplasia or squamous cell carcinoma.