Skin neoplasms have been relatively easily diagnosed because of its occurrence on the skim surface and these tumors respond well to surgical treatments. But skin neoplasms have variable clinical characteristics according to individual
variation.
Recently, several markers for proliferating cells have been found and, with antibodies to these markers, immunohistochemical studies have been performed. However. almost all of these markers require freshly frozen tissues for evaluation :
therefore reurospective study of formalin fixed tissues is impossible.
The proliferating cell nuclear antigen(PCNA) is one of the cell cycle dependent nuclear antigens that increases in the late G1 and S phases. Nucleolar organizer region(NORs) are DNA loops encoding ribosomal RNA production. Detectable
by
the
argyrophilia(Ag-NORs) of associated proteins. PCNA and Ag-NORs have enabled us to investigate paraffin embedded tissues and thus retrospective studies is possible. The mean expression rate of PCNA and mean number of Ag-NORs are
correlated
with
the growth fraction and may have diagnostic and prognostic value in other tumors.
For understanding the charateristics of variation in clinical appearance, correlation between the clinical findings and cell proliferating activities were investigated. Cases examined were as follows;20 cases of seborreic keratosis as benign
neoplasms, 15 cases of actinic keratosis and 13 cases of Bowen's disease as precancerous lesions, 22 cases of basal cell carcinoma and 27 cases of squamous cell carcinoma as malignant neoplasms. In each case, cell proliferating activities
were
calculated and comparison was performed accoreing to age, sex size duration, anatomic location, degree of malignancy and depth of histologic invasion.
@ES The results are as follows :
@EN 1. The cell proliferating activities were significantly increased as degree of malignancy increased, as observed by PCNA and Ag-NORs(P<0.05).
2. When the cell proliferating activities were compared according to duration in each neoplasm. the mean expression rate of PCNA in actinic keratosis significantly increased in shorter than one year and mean number of Ag-NORs in basal cell
carcinoma significantly increased in cases shorter than one year(P<0.05).
3. When the cell proliferating activities were compared according to size in each neoplasm, the mean expression rate of PCNA and number of Ag-NORs significantly increased in cases larger than 1cm2(P<0.05).
4. The cell proliferating activities were not correlated to age, sex anatomical location and depth of histologic invasion.
5. In the other analysis of clinical findings, regionally the most common sites were the head and neck region in skin neoplasms, actinic keratosis and basal cell carcinoma was more common in the females than in males, the precancerous
lesions and malignwant neoplasms unlike benign neoplasms were more common in age group exceeding 61 years of age.
In conclusions, the PCNA and Ag-NORs is a valuable marker in deciding the degree of malignancy. The malignant potential of actinic keratosis is thought to be decided early in it's stages, this is because the cell proliferating
activities
of
early stage and small sized actinic keratosis is increased. Thus, must be treated in it's early stages. Also the characteristics of basal cell carcinoma is thought to be decided the in early stage although it shows slow growth clinically.
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