Involucrin (molecular weight 92000 daltons) is a soluble cytoplasmic precursor of the cross-linked protein envelope that appear late in the terminal differentiation pathway of keratinizing squamous epithelia. In normal epidermis, this protein is
present
in the maturing cells of the upper stratum spinosum and the stratum granulosum, but is abscent in the basal layer. In a recent study, immunohistochemical localization of involucrin was shown to be a specific marker for squamous differentiation
and
maturation in various tumors.
The auther investigated the Involucrin expression by an immunohistochemical study on its distribution in normal and neoplastic tissues of the larynx.
@ES The results were as follows:
@EN 1) Normal laryngeal tissues revealed homogenous cytoplasmic staining in the superficial layers and intermediate layers.
2) In epithelial hyperplasia groups, diffuse cytoplasmic staining was seen in the upper layers.
3) Focal staining was showed in the invasive carcinoma and he higher it differentiated, he stronger it stained.
Results of this study suggest that involucrin is sensitive and specific marker for squamous differentiation, and staining patterns for Involucrin nay be helpful in distinguishing benign from malignant lesion. (Korean J Otolaryngol 38:10, 1995)
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