[Response of collagenous tissue to pigmented tumors]

Using microradiograms (x-rays of histological sections) and polarized light, we examined collagenous tissue surrounding junctional nevi, benign juvenile melanomas, Dubreuilh's melanosis and early malignant melanomas similar to junctional nevi. Wherever there were tumor cells and infiltrates the collagenous tissue was reduced or destroyed, but had not usually been pushed aside as claimed in previous accounts. The absence of a connective tissue membrane, comparable to the border-zone beneath the epidermis, argues against a nevus. Mature collagenous bundles are clearly shown up by microradiograms and by pollarized light. The degree of thier destruction does not make it possible to distinguish between nevi and malignant melanomas.