Nuclear morphometry in solar keratosis.

OBJECTIVE: To carry out a feasibility study for the development of procedures for the objective characterization and grading of solar keratotic skin lesions. STUDY DESIGN: Imagery from sections of skin shave biopsies from 12 light-skinned individuals were digitized. A minimum of 25 nuclei from a solar keratotic lesion and 25 nuclei from a location in histologically normal appearing skin adjacent to the lesion were recorded for each case. Values of karyometric features were computed, and a discriminant function distinguishing normal nuclei from nuclei exhibiting solar irradiation damage was derived. RESULTS: Approximately 50% of nuclei in solar keratotic lesions were markedly affected by solar irradiation, but even in biopsies from histologically normal appearing skin, 3-30% of nuclei showed signs of such damage. Nuclei from solar keratotic lesions exhibiting such damage had numerous morphometric and karyometric features commonly found in malignant cells. The state of progression of a solar keratotic lesion can be graded by a plot of proportion of nuclei exhibiting solar damage versus the average discriminant function score of the most affected nuclei. This plot provides a monotonically rising progression curve and a numeric grading score. CONCLUSION: Karyometry of nuclei from skin biopsies allows objective assessment of the progression of solar keratotic lesions. Similarity of feature values in nuclei from solar keratotic lesions to those in malignant lesions was noted. The progression curve derived in this study could serve to measure the efficacy of chemopreventive or therapeutic intervention.

Chronic solar ultraviolet damage associated with malignant melanoma of the skin.

A retrospective study of 226 cases of cutaneous malignant melanoma (CMM) was done to determine if patients with CMM showed evidence of chronic solar ultraviolet radiation damage, i.e., a past history of actinic keratosis (AK), basal cell carcinoma (BCC), squamous cell carcinoma (SCC) anywhere on the patient's skin, and solar elastosis (SE) at the site of a CMM. This statistical analysis consisted of 119 clinical records and 158 pathology slides after all cases of lentigo CMM were deleted. CMM showed no statistical correlation with AK, BCC, SCC, or SE. This supports the idea that it is not the chronic solar-ultraviolet radiation exposure that causes CMM.

Malignant melanoma in southern Arizona. Increasing incidence and sunlight as an etiologic factor.

This study demonstrated an increasing incidence of malignant melanoma during the past ten years and a very high incidence of this tumor in southern Arizona. During the ten-year period, 533 melanomas were removed from white patients. Of these, 52% were male and 48% were female. The number of melanomas increased yearly, from 20 in 1969 to 120 in 1978, a crude rate incidence of 6.49 to 28.57 (27.20 standardized) per 100,000, respectively. This reflects an average annual increase of 34% to 37% and a 340% increase for the period. The highest incidence of tumor was in the 50 to 59 year and 60 to 69 year age groups. The most common site of occurrence was the back, with twice as many tumors arising there in males. The legs were involved in 13% of patients, with an occurrence rate eight times higher in females. The extremely high incidence of melanomas in southern Arizona is probably due to meteorologic and geographic factors allowing large amounts of ultraviolet light to reach the earth's surface.

Formalizing physician input in equipment decisions.

The Tucson Medical Center has established a special equipment committee, consisting of representatives from the medical staff, administration, purchasing, and biomedical engineering, to handle its many special equipment purchase requests. This joint responsibility in decision-making has widespread acceptance among physicians and administrators. The institution's rigorous procedure and its subsequent benefits are outlined.