[Laryngeal epithelial dysplasia vs. laryngeal intraepithelial neoplasia].

Laryngeal cancer is the most frequent malignancy of the upper respiratory tract. Only the very early treatment of tumors or even of their precursor lesions will be both curative and organ preserving. Microsurgical techniques facilitate early detection and complete removal of limited lesions can be achieved quite frequently, but follow-up data for such lesions are difficult to obtain. The resulting lack of endpoint observations (i.e., malignant transformation, spontaneous involution) hampers the development, testing, and application of grading systems focusing on epithelial alterations, especially changes with only mild nuclear atypia and minimal structural alteration. Such lesions may be entirely benign or may indicate premalignant stages of well-differentiated carcinoma. For diagnosis we recommend a modified Kleinsasser's system to classify premalignant epithelial changes. Only the complete removal of suspicious lesions as far as possible or regular clinical follow-up in cases where complete removal cannot be achieved can prevent the development of advanced stage cancer.