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S9C14VA1-1: The interface between reticular dermis and subcutaneous tissue is represented. A normal relationship is represented on the left with a black line defining the interface; this interface can be traced by a
broken line across the field to the right; it has an undulating quality. The woven pattern of collagen bundles in the normal reticular dermis is represented; there is a faint yellow background which might be taken
to represent the elastica of the dermis. On the right, there are continuous black lines above, and below, the broken line (original boundary line). In the areas between the two continuous black lines, with the
broken line placed centrally, the collagen bundles are arranged in parallel arrays. These relationships give recognition to the fact that the sclerosing process of morphea
(and of other sclerosing processes involving this interface, such as necrobiosis lipoidica and LE profundus) affect tissues on both side of the boundary; they proceed upward into the dermis and downward into the adipose tissue. This drawing also conveys temporal relationships. The vector of time is directed to the right; a young pattern is represented to the left, a maturing lesion is represented centrally, and a mature lesion is represented on the right. In the maturing area, lipocytes are represented in yellow and have been entrapped in the expanding fibrous matrix. In this altered environment, they will undergo atrophy. Lipocytes are not included in the matrix of the mature lesion on the far right. It seems proper to characterize the newly formed fibrous tissue below the broken line as the product of
substitutive fibrosis; the fibrous tissue has intruded into the domain of the lipocytes. A characterization of the fibrosing process above the broken line is more difficult. If the process of fibrillation of
collagen bundles is an accommodation favoring the deposition of fibrils within the fissures that have formed in collagen bundles, the process might be characterized as intra-bundle growth
(i.e., interstitial); if it is deposited among the pre-existing collagen bundles and along the surfaces of the bundles, it might be characterized as accretive growth. If there is lysis of collagen and, in
its stead, a deposition of immunologically altered collagen, then the process is substitutive.
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