MODIFICAZIONI ISTOPATOLOGICHE TUSSUTALI IN CORSO DI ESPANSIONE CUTANEA

Results are reported of a study of the structural changes taking place in tissues under skin expansion. Numerous biological parameters were assessed. These were ploidia, DNA content, autoradiography and immunehistochemistry under optic and electron microscopy. Epidermis: The cells are intact. The basal layer and the waves of the basal lamina are accentuated. No reduction of the intercellular spaces reported by other workers was noted. Dermis: Thinning of dermis despite increased fibroblastic activity was found. Elastic fibres appeared to be fragmented. Skin appendages: Normal in function and number but more widely separated over the expanded area. Capsule: Composed of numerous parallel bundles of connective tissue of varying density with inflammatory infiltration and birefractory particles resembling silicone. Nevertheless the most interesting features emerged from the study of the mitotic index and zonal microcirculation. Investigation of cell kinetics showed an increase in the proliferative activity of the skin with a mitotic index 4 times greater in the expanded skin in relation to pre-operative values. A marked increase in vascularisation was noted in promixity to the outer layer of the capsule around the prosthesis. New angiogenetic vessels in this area provide highly vital flaps of expanded skin.