F2Ch12 (113049): The epidermis shows compact hyperkeratosis and hypergranulosis. The basal unit is hyperplastic with elongated rete ridges. There is mild, irregular melanocytic hyperplasia in the basal layer of the epidermis. Collagen bundles are wavy; they vary in size. A pale fibrous matrix separates the more acidophilic collagen bundles. There is an increased number of mononuclear cells in the dermis. A distinctive papillary dermis is not a feature. Dilated vessels show mild endothelial cell hyperplasia. Near the left margin of the field, fragments of acidophilic basement membrane material have collected near the dermal-epidermal interface. The follicle is outlined by a glassy membrane at this superficial level.

F3Ch12 (113049): The glassy membrane of a follicle is brightly acidophilic. Some of the fibers in the adjacent dermis have tinctorial qualities that are similar to those of the glassy membrane. It seems unlikely that these fibers are markers for a movement of the domain of the follicle away from an earlier site; we might consider the possibility that the material is of dermal origin; it is not representative of a normal component of the reticular dermis. The background matrix is also fibrous; an interstitial mucinous component is inconspicuous.

F4Ch12 (113049): The domain of the reticular dermis is represented; above the fibrous component of a fibrous papule is represented. Below the center of the field, collagen bundles are loosely arranged; the interstitial spaces are widened. At the interface, multinucleated giant cells loosely distributed; they are interpreted as histiocytic giant cells. Commonly, giant cells collect at the interface between the lesional fibrous tissue and the less involved portion of the reticular dermis. It would be of interest to compare the patterns of elastic fibers in the lesional fibrous tissue with those of the zones of collagenolysis.

F5Ch12 (113049): Lesional fibrous tissue of a fibrous papule is represented at the top of the field. Deep to this zone of sclerosis, the collagen bundles are reduced in size and are loosely spaced. Giant cells are present among the altered collagen bundles; the relationships are such that the giant cells would appear to be engaged collagenolysis. In the area of collagenolysis, some of the fibers are interpreted as elastic fibers.

F6Ch12 (113049): This is a portion of the field seen in F5 but the orientation is different. Some of the fibers in the more open spaces are interpreted as elastic fibers. The cytologic features of the giant cells are more in keeping with histiocytic giant cells than with some variation of a fibroblast.

F7Ch12 (113049): This also is a portion of the field seen in F5 and again the orientation has been changed. The dilated vessel to the right shows endothelial hyperplasia.