Laryngeal keratosis preceding laryngeal carcinoma. A report of four cases.

Detailed descriptions of the laryngeal mucosal changes that precede squamous cell carcinoma are infrequent. The criteria for identification of epithelial changes that are considered "premalignant" vary widely among pathologists. Presented herein are the histological details and clinical findings of four patients with biopsy-proved laryngeal keratosis in whom laryngeal carcinoma subsequently developed over intervals ranging from ten months to six years. The epithelial changes are variable but generally consist of a thickened mucosa with prominent alterations in the pattern of maturation. These maturation abnormalities range from proliferation of immature "basal-like" cells with little or no surface keratinization (classic form of atypia or dysplasia) to markedly thickened mucosa with prominent keratinization, both on the surface and in individual cells in the deep portions of the mucosa. Multiple recurrence in two of the patients with mucosal thickening and extensive individual cell and surface keratinization suggest that not only this histopathologic change, but the propensity for recurrence, may both be indicators of premalignant epithelial change.