S9C28P19NLD



S9C28P19-1: In this area of a lesion of NLD, the collagenous changes are characteristic; collagen bundles are pale. They are streaked in parallel arrays. The area is relatively acelluar (necrotic). There is hyperelastosis to the left and below the center of the field, but this is interpreted as a coalescence of elastic fibers in response to focal lysis of the collagenous component. Elastic fibers can be traced from the rich zone on the left into the elastica-free zone on the right. Along this course, the fibers loose their affinity for the specific Verhoeff stain; they become pale and greyish-yellow. They are also reduced in number and the diameter of individual fibers is reduced. Blue arrows identify a small cluster of these altered fibers. Elastolysis has been caught in the act.

S9C28P19-2: Vascular changes in a variety of patterns are common in lesions of NLD. In this field, granulomatous infiltrates are present at the top of the field in the adventitia of this vein. Below the center of the field, a granuloma has interrupted the media of the muscular vessel. To the right of the center of the field, the intima of the muscular vessel is thickened and fibrotic; in this area, the lumen is narrowed.

S9C28P19-3: A muscular vessel shows edema of the media with infiltrates of lymphoid cells in both the media and in the neighboring adventitia. A blue arrow points to a multinucleated giant cell.

S9C28P19-4: This small vessel shows an occluded lumen with fibrin deposits (red fibrils) outlining the lumen and extending into the wall. Connective tissue cells of the wall are activated. The debris, centrally in the lumen of the vessel, probably represents degenerating cells. Changes of this type may be related to the focal infarcts commonly found in lesions of NLD.

S9C28P19-5: The changes affecting this vessel include a narrow lumen and endothelial swelling. The concentric duplication of fibers in the wall probably represents a duplication of basement membrane material. There are mild perivascular infiltrates of lymphoid cells. The patterns qualify as a diabetic vasculopathy in a lesion of NLD.

S9C28P19-6: The wall of this vessel is thickened and hyalinized; the lumen is markedly narrowed (diabetic vasculopathy of NLD).

S9C28P19-7: In this area of a lesion of NLD, the connective tissue below the center of the field is acellular. In this acellular zone, collagen bundles are swollen and pale; this alteration qualifies as necrobiosis. Many of the collagen bundles are arranged in parallel arrays. On the right, superiorly. Focally, lymphoid cells are regularly spaced among the thin collagen bundles. This loose fibrous matrix is viable and edematous. At the interface between viable and necrotic tissue, both centrally and to the left, a column of squamous cells defines the boundary. On the side facing the viable tissue (above), a basal epithelial layer is well-defined. On the side facing the necrotic tissue (below), a basal epithelial layer is not well defined. The epithelial column is an expression of pseudoepitheliomatous hyperplasia (keratinocytic immunoproliferation); its extremity is claw-shaped. This configuration may be anticipatory of a later stage in which necrotic tissue might perforate the epithelial column and, eventually, might be delivered to the skin surface.

S9C28P19-8: At the top and at the bottom of the field, viable (nucleated) cells are represented among collagen bundles; the dermis in these areas is viable. Centrally and extending to both margins, the dermis is acellular (with the exception of a small focus on the right above the center of the field). In the acellular areas the dermis is necrotic, but architectural features are preserved (necrobiosis). Collagen bundles in the zone of necrobiosis are pale, swollen, and mostly arranged in parallel arrays. The bright, linear deposits, among, and along, the surfaces of the collagen bundles in the area of necrobiosis, represent deposits of fibrin. Granulomas are not a prominent feature at the interfaces between viable and necrotic tissue (the pale area is another example of the pattern that is most deserving of the term, necrobiosis).

S9C28P19-9: Plasma cells often are a prominent feature of the inflammatory infiltrates of NLD. In contrast, the infiltrates of granuloma annulare rarely contain a component of plasma cells. Some of the plasma cells in this field show a prominent hof (perinuclear halo) (red arrows).

Up one tier if at tier 3, then up to respective parent CHAPTER; if at tier 2, then HOME

Next page sequential along a tier

Back a page spatial not temporal

Mauve bars provide access to other SECTIONS of this site

Green bars provide access to web sites

Beige bars provide access to additional photomicrographs and to parent CHAPTERS; they provide access to material not accessible with above cluster of Beige buttons