AgNOR staining in melanocytic skin lesions

Cho, Kwang Hyun; Kim, Young Gull; Lee, Seung Chul; Han, Eui Keun

Abstract

BACKGROUND: Histological differentiation between malignant melanoria and benign melanocytic skin lesions is at times, a difficult task for the dermatopathologist. The AgNOR staining has been regarded as a useful tool in differentiating malignant melanoma from benign rael;inocytic nevi.
OBJECTIVE
We have carried out the AgNOR staining in a range of nelanocytic lesion and try to assess the value of AgNOR stairting in the identification of malignancy in melanocytic lesions. METHOD: Fifty seven melainocytic skin specimens were studied. These comprised 11 acquired melanocytic nevi, 11 congenital melanocytic nevi, 31 malignant melano nas and 4 atypical melanocytic hyperplasias. RESULT: The majority of benign nevus cells posessed one or two unifrm AgNORs, whereas marked AgNOR pleomorphism was found in some rnelanoma cells. The number of AgNORs per nucleus. averaged 1.24+0.12 in the 18 specimens of benign nevi and 2.10+0.6 in the 25 specimens of malignant melanoma. In the cases of atypical melanocytic hyperplasia it was not possible to count on an adequate number of cells to give a meaningful result because of melanin pigment.
CONCLUSION
Although this study demonstrated a separation of average AgNOR counts between begnign melanocytic nevi and maligmant melanomas, there was an ovei lap in counts among individual lesions. For clinical use, there should be a standard method by which AgNORs are counted in AgNOR staining. Melanin pigment masiking the AgNORs can also be a problem.