Inherited systemic amyloidosis (Finnish type): ultrastructure of the skin.

Ultrastructural study of skin biopsies from two patients suffering from inherited systemic amyloidosis (Finnish type) showed amyloid deposits between epidermal basal cells and dermal fibroblasts. Amyloid was seen on the epithelial side of the fibroblasts, and material resembling basal laminae was embedded in the aggregates of amyloid. Also amyloid deposits were found adjacent to other cells with a basal lamina such as epithelial cells of the sweat glands or sebaceous glands, Schwann cells, capillary endothelial cells, and even smooth muscle cells in the dermis. Amyloidogenetic interaction of cells with a basal lamina and fibroblasts is suggested and the potential role of structural glycoproteins in the genesis of amyloid is discussed.