Abstract
By using cumulative survival curves the influences of histological criteria of the primary tumour on the prognosis of 204 patients with clinical stage I malignant melanoma were evaluated. Tumour thickness, level of invasion in the dermis plus ulceration appear to have greatest influence on prognosis. Other factors influencing prognosis include the histogenetic type of melanoma, malignant cell invasion into blood vessels as well as intralesional transformation. On the other hand, it appears from our material that the number of mitoses, the type of malignant cell, regression phenomena and the amount of the inflammatory cell infiltrate have no significant influence on prognosis.