About 95% of laryngeal cancers are typical squamous cell carcinomas. Rarely, adenocarcinomas are seen, presumably arising from mucous glands. The tumor develops directly on the vocal cords (glottic tumors) in 60% to 75% of cases, but it also may arise above the cords (supraglottic; 25% to 40%) or below the cords (subglottic; <5%). Squamous cell carcinomas of the larynx begin as in situ lesions that later appear as pearly gray, wrinkled plaques on the mucosal surface, ultimately ulcerating and fungating (
Fig.
13.49 ). The glottic tumors are usually keratinizing, well to moderately differentiated squamous cell carcinomas. As expected with lesions arising from recurrent exposure to environmental carcinogens, adjacent mucosa may demonstrate squamous cell hyperplasia with foci of dysplasia, or even carcinoma in situ.
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Fig. 13.49 Laryngealsquamouscellcarcinoma(arrow) arisinginasupraglotticlocation(abovethetruevocalcord).
Carcinoma of the larynx manifests clinically with persistent hoarseness. The location of the tumor within the larynx has a significant bearing on prognosis. For example, about 90% of glottic tumors are confined to the larynx at diagnosis. First, as a result of interference with vocal cord mobility, they develop symptoms early in the course of disease; second, the glottic region has a sparse lymphatic supply, and spread beyond the larynx is uncommon. By contrast, the supraglottic larynx is rich in lymphatic spaces, and nearly one-third of these tumors metastasize to regional (cervical) lymph nodes. The subglottic tumors tend to remain clinically quiescent, usually manifesting as advanced disease. With surgery, radiation therapy, or combination treatment, many patients can be cured, but about one-third die of the disease. The usual cause of death is widespread metastases and cachexia, sometimes complicated by pulmonary infection.
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