Ultrastructural investigations of finger pulp biopsies: a study of 31 patients with Raynaud's syndrome.

Finger pulp biopsies of 31 patients suffering from Raynaud's syndrome (RS) were investigated by light and electron microscopy. The patients suffered from various underlying diseases. Interest was focused on the vascular changes and nerve and connective tissue alterations, especially the elastic fiber changes. In the dermal capillaries, endothelial swelling, narrowing of the lumen, increased numbers of intracytoplasmic filaments and Weibel-Palade bodies, and various types of basement membrane alterations were observed. The basement membrane of the unmyelinated nerves showed similar alterations to the capillary basement membrane. Severe degenerative changes were found in the myelin sheath of the myelinated axons. In the dermal connective tissue, severe elastotic degeneration and alterations of the collagen fibers were observed. The data probably represent the ultrastructural picture of the end stage of this syndrome.