Photometric evaluation of laryngeal epithelium exhibiting hyperplasia, keratosis and moderate dysplasia.

Photometric examination of vocal cord epithelia disclosed no difference in the nuclear DNA content or nuclear area of normal and keratotic laryngeal epithelia. For 2 out of 3 epithelia displaying hyperplasia the values were slightly elevated. There seem to be no morphologic or photometric grounds for considering either hyperplasia or keratosis to be premalignant. Eight patients with moderate dysplasia were selected; 3 with and 5 without subsequent development of severe dysplasia or carcinoma in situ. In all 8 cases the DNA values were not increased, but in 6 there was an increased variation about the mean. There were no morphologic or photometric differences between the epithelia subsequently developing severe dysplasia or carcinoma in situ and those that did not. The 3 patients developing severe dysplasia or carcinoma in situ were then followed for 112, 27 and 106 months and showed no evidence of invasive carcinoma. The other 5 patients with moderate dysplasia were followed for 48 to 123 months without any sign of recurrent disease. There are no photometric grounds for considering moderate dysplasia as a precancerous lesion. Long-term investigation is required to ascertain the risk that carcinoma in situ or invasive carcinoma will develop in patients with laryngeal hyperplasia, keratosis and moderate dysplasia.