Diagnosis and grading of malignancy in squamous epithelial lesions of the larynx with DNA cytophotometry.

For diagnostic purposes 14 histologically benign, 15 dysplastic, and 16 malignant squamous epithelial lesions were subjected to DNA cytophotometry. Results were computed according to an algorithm for DNA diagnosis and grading of malignancy. In cases of unequivocally malignant or benign lesions all DNA diagnoses agreed with the histologic diagnoses. In one case the allegedly faulty DNA diagnosis of cancer was proven to be correct on clinical follow-up. Within the group of histologically mild to moderate dysplasias the algorithm identified four cases as malignant that were proved to be malignant either in the follow-up or at another site of the same lesion. With the aid of the DNA malignancy grade two groups of patients with squamous epithelial carcinomas of the larynx could be discerned with a highly significant difference according to their survival times.