Collagenase immunolocalization studies of cutaneous secondary melanomas.

Immunoreactive collagenase has been demonstrated in 5/14 specimens of cutaneous secondary melanomas. In contrast, very little enzyme was seen in 10 specimens of normal human skin. All specimens were fixed within minutes of excision. These findings support the hypothesis that collagenase facilitates connective-tissue breakdown which is associated with tumour invasiveness and metastatic spread.