Malignant tumours in patients with non-invasive squamous cell lesions of the vocal cords.

The concept of 'field cancerization' is applicable throughout the upper aerodigestive tract, oesophagus and lung. The material for this study consisted of 232 patients with hyperplasia, keratosis with or without dysplasia, and carcinoma in situ of the vocal cords. The overall risk for these patients with non-invasive squamous cell lesions of the vocal cords to have or to develop an independent, primary malignant tumour was 12.9% (30/232). Carcinomas of the head and neck, lung or oesophagus were diagnosed in 8.2% (19/232) of the patients. Patients with hyperplasia, keratosis, dysplasia and carcinoma in situ of the vocal cords should be carefully followed-up, not only as progression to invasive carcinoma may occur many years after the initial diagnosis, but also as there is a high incidence of independent primary tumours, especially of the multicentric type.