Observations of the pathologist on precancerous lesions of the larynx. Integrated with histological data and quantitative analysis of nuclear DNA content

It is the impression of pathologists that a multicentric origin of a dysplastic process in the larynx is not a rare event. The otologists suggest something more, to wit that the same factor which damages the laryngeal mucosa, thus giving rise occasionally to a carcinoma, damages other tissues as well, and not only tissues of the larynx: it attacks areas further down the respiratory tract, especially the bronchioles. Of 409 lung carcinomas studied at autopsy, 41 were associated with malignant tumors of other viscera. Undoubtedly, the larynx is the viscus which is the most frequently affected in this association. As regards the dysplasias, leukoplasias and the carcinomas in situ, the microinvasive cancers, and the cases of Bowen's disease are as sharply separated from the true carcinomas by some authors. The argument that cancers in situ are nonetheless cancers because statistical studies are in agreement in pointing out the course of the lesion towards an infiltrative carcinoma (even up to an interval of 5 to 10 yr). However, precisely here lies the importance in identifying these forms as early as possible; and then, a clinician, well convinced of what will follow, has sufficiently long time in which to interrupt a fatal course. Therefore, both groups of lesions should be evaluated in a single discussion: the precarcinomas and the early carcinomas on the one hand, because they still can be cured by not mutilating operations; and on the other hand the invasively growing carcinomas, which often need a total laryngectomy. Studies of Sirtovi (1963, 1964) and Kleinsasser (1964) which represent fundamental stages in this regard, are in accordance with these conclusions. Sirtovi is of the opinion that the major part of so-called relapses occur in the larynx, because in this region, more so than elsewhere, the carcinoma has a progressive character. Kleinsasser agrees with this statement and affirms that sooner or later a carcinoma in situ evolves towards a carcinoma in 90% of the cases