S8C35P21-1: Hans Selye expended time and effort promoting his concepts of “stress syndromes.” Calciphylaxis was a special variant in which a stress (usually a form of induced inflammation) was associated with the deposition of calcium in the sites of stress, including the walls of blood vessels. The concept currently has gained popularity as a label for diseases of the skin and fat in patients in renal failure, particularly renal dialysis patients. In this form of panniculitis, necrosis of fat and thrombosis of vessels are prominent features. In this example, the dermis is fibrotic; it appears to be acellular beneath a plate-like zone of necrosis and acute inflammation (above the blue arrows). A red arrow points to a thrombosed vessel in the lower portion of the dermis. The dermis is fibrotic; collagen bundles in areas are streaked in a direction that is parallel to the skin surface (the changes at the lower margin of the dermis are sclerodermoid; sclerodermoid changes are common in association with some forms of vascular insufficiency). The interface between the dermis and subcutaneous fat is straight (another sclerodermoid feature). The epidermis, and the upper portion of the dermis (above the plate-like zone of inflammation) are necrotic (infarcted or gangrenous) ( calcifying panniculitis of renal failure).

S8C35P21-2: In this field, at scanning magnification, the dermis centrally, and to the left, is necrotic; it is infiltrated with neutrophils (a pattern that qualifies as wet gangrene). The necrotic dermis has separated from the inflamed adipose tissue. The inflammation is diffusely distributed among the lipocytes of the lobules; the pattern is that of a lobular panniculitis (calcifying panniculitis of renal failure , complicated by ulceration).

S8C35P21-3: To the right, the vacuoles are lipid-filled spaces produced by the release of cytoplasmic lipids as a result of the breakdown of necrotic lipocytes. The pale patterns among the vacuoles are the representative of infiltrates of epithelioid histiocytes among the vacuoles; the patterns, in this area, are lipogranulomatous. To the left and below the center of the field, a vessel is cut in cross section. Fibrin is present in the lumen The wall of the vessel is calcified (calciphylaxis); the calcium is lavender and the deposit is fractured. The surrounding tissue is necrotic; the basophilia of the surrounding zone is contributed by the break-down of the nuclei of inflammatory cells.