DEOXYRIBONUCLEIC ACID CONTENT OF EPIDERMAL IN-SITU CARCINOMAS

DNA ploidy of primary hepatocellular carcinoma and pulmonary metastases

To better comprehend the differences in deoxyribonucleic acid (DNA) content between a primary hepatocellular carcinoma (HCC) and pulmonary metastatic nodules, tissue specimens taken at autopsy of 25 patients who had not received any drugs to treat the malignancy were examined using microspectrophotometry. The DNA distribution patterns were classified into Types I-III, and low (Types I and II) or high (Type III) ploidies, according to DNA distribution. Changes in the DNA content from high to low ploidies, namely DNA ploidy reduction from the primary lesion to pulmonary metastatic lesions, was evident in 9 of the 25 patients (36%), and changes from low to high were noted in 2 of the 25 patients (8%). The remaining 14 (56%) showed no evidence of changes in the DNA ploidy pattern. Reduction of DNA ploidy seen in HCC and its metastatic lesions in the lung may be one of the aspects of clonal evolution or selection mechanisms during the progression of tumor growth and metastasis.

Biology of cutaneous squamous cell carcinoma

Nonmelanoma skin cancer is the leading cause of cancer in the United States. Cutaneous squamous cell carcinoma is second only to basal cell carcinoma in prevalence and its incidence is increasing. The biology of squamous cell carcinoma is reviewed under the broad areas of etiology, immunobiology, biochemistry, metastatic potential, and therapy, with emphasis on prevention, diagnosis, and management.

Investigation of DNA-content of leukoplakia cells or oral mucosa

DNA-histograms of smears of 11 plain leukoplakias, one of a precancerous leukoplakia, three of leukoplakia carcinoma in early stage, and one of a keratotic seqamous cell carcinoma of the floor of the mouth were prepared. The cell nuclei of the plain leukoplakia are mostly diploid, a small proportion has a DNA-content of 4 C. Intermediate values or polyploid nuclei are absent. In precancerous leukoplakia, intermediate values were noticed; in the cases of carcinoma in early stage, intermediate and polyploid nuclei were present, and in one case only polyploid nuclei. Only 2C and 4C nuclei occurred in a case of keratotic squamous cell carcinoma, which in comparison to earlier examined cases must be termed DNA negative.

Chromosomes in precancerous lesions and in carcinoma of the uterine cervix

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