S9C15aP7aLinearScleroderma

S9C15aP7a-1: This is an example of linear scleroderma. The patient was an infant. The lesion had produced a contraction deformity of the involved extremity. Fibrous tissue of the dermis extends below the level of the sweat glands; the glands are “entrapped.” The pattern, in the band of fibrous tissue below the level of the sweat glands, is abnormal. The interface between the dermis and the subcutaneous tissue is straight. The fibrosing process involves the septa of the subcutaneous fat; they are widened. The superficial layer of the deep fascia is also involved (focally, the replacement of fat by fibrous tissue might be cited as a histologic correlate of a clinical pattern of en coup de sabre). In the affected areas of the dermis and in the affected septa and fascia, collagen bundles are coarsened. They are streaked in a direction that parallels the surface of the skin (the patterns in the septa being the exception). A zone of pale fibrous tissue forms the interface between the altered dermis and some of the lobules of adipose tissue ( substitutive fibrosis); it also outlines some of the fibrous septa.

S9C15aP7a-2: The upper portion of the reticular dermis is edematous and shows interstitial infiltrates of lymphocytes and histiocytes. Below the plane, which is both parallel to the skin surface and just below the extremities of the hair follicles on the right, collagen bundles are straight; they are parallel to the skin surface. This alteration of the direction of the collagen bundles is a characterisitic feature of cutaneous lesions of scleroderma ; it is a feature closely associated with substitutive fibrosis. It is, in part, a pattern of interstitial and accretive fibrosis. As a result of the process of substitutive fibrosis at the lower margin of the dermis, the vertical dimensions of the dermis have been increased; an expanse of new fibrous tissue has been formed in the lower portion of the dermis. The newly formed fibrous tissue has incorporated a portion of the domain of the subcutaneous tissue.

S9C15aP7a-3: The fibrous septum, which courses diagonally across the field from right to left, is coarsened; it shows streaking of altered collagen bundles. There are interstitial infitrates of lymphoid cells among the collagen bundles, and in the neighboring lobules of fat. The pale fibrous tissue, at the lower margin of the dermis and among lipocytes in the lobule above the septum, is the product of substitutive fibrosis. In the lobule to the right of, and below, the septum, substitution has progressed to the point of having replaced most of the lipocytes; the pattern, in the latter area, qualifies as fibrous atrophy of fat.

S9C15aP7a-4: In this area of fibrous atrophy of fat, only a few lipocytes remain. The vessel outlined by green arrows shows a pattern of a lymphocytic vasculitis. The vasculitis is of a type commonly seen in the setting of collagen-vascular disease.

S9C15aP7a-5: The interstitial infiltrates of lymphocytes and histiocytes qualify as a pattern of a lymphohistiocytic collagenosis. This pattern of interstitial inflammation is also common in the setting of other collagen-vascular diseases; it is not peculiar to morphea or scleroderma.

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