Skin lesion in mixed cryoglobulinemia

Biopsy of a purpuric skin lesion in mixed cryoglobulinemia with PAS stain. Cryoprecipitates, which are intensely PAS-positive, can be seen occluding multiple vessels (left panel). High-power view (right panel) shows both cryoprecipitates and the deposition of fibrin in the vascular lumen and vessel wall.