歯肉病変における細胞核DNA量の研究

特に歯肉癌とその境界病変について

抄録

Nuclear DNA content was detemined in 85 subjects made up of 29 patients with carcinoma of the gingiva, 26 with bordering pathological findings (23 with leukoplakia and 3 with epithelial dysplasia), 20 with non-cancerous epithelial hyperplasia (10 with epithelial hyperplasia and 10 with papilloma) and 10 subjects with normal gingival mucosa, and then compared with the histological findings to clarify relationships to cell maturation and tissue differentiation. Measurement of nuclear DNA content was performed by cytofluorometry for cells of the outer and inner layers of cancer nest in carcinomas and for cells of the basal and prickle layers of the epithelium in the other lesions. The results were as follows:
In 56 subjects exclusive of patients with carcinoma, nuclear DNA content was higher in the basal layer than in the prickle layer. Particularly in normal gingivae, histograms showed 4 single peak with mode at 2C for the basal layer and under 2C for the prickle layer.
The distribution of DNA content was limited within 4C. In non-cancerous epithelial hyperplasias, nuclear DNA content, particularly that of the basal layer, increased as compared with normal mucosa, and increased in papilloma but not in epithelial hyperplasia.
In borderline lesions, nuclear DNA content slightly increased in Grade I and Grade II leukoplakias compared with normal mucosa, while it markedly increased at the basal layer in Grade 111 leukoplakia featuring cellular atypia and at both the basal and prickle layers in epithelial dysplasia, with the pattern of change sometimes resembling that in carcinoma. In carcinomas in situ, no appreciable variation dependent on the site of measurement was observed in the histogram pattern.
In squamous cell carcinomas, nuclear DNA content was generally high but sometimes close to that in normal mucosa, and the histogram pattern showed a tendency towards diversification.Analysis of relationship between the degree of differentiationo and the nuclear DNA content in squamous cell carcinoma disclosed that nuclear DNA was higher in the outer layer of cancer nest than in its inner layer in just over 82% of well-differentiated or moderately-differentiated carcinomas. As carcinoma became less and less differentiated, the modal peak in histograms, particularly those for the outer layer of cancer nest, shifted further to the right and a more flattened pattern resulted while hyperploidy cells occurred with increased frequency, particularly in moderately-differentiated carcinomas.