Figure 4

(a) "Mucosal" reaction pattern of CHC in a skin flap. The epidermis (E) shows absence of orthokeratinisation, which is difficult to observe at this magnification, variably desquamating parakeratinising layers (area in rectangle) and irregular hyperplasia (acanthosis). Nodular/perivascular chronic inflammation and fibrosis expand the reticular dermis (asterisk). Subcutaneous fat and sweat glands (S) are seen, which allows confident identification of the flap. The area in rectangle is magnified in Fig. 4b. (b) The absence of orthokeratinisation and desquamating parakeratinised layers are better appreciated here. (c)Adjacent section stained with PAS shows individual hyphae (arrowheads) between desquamating keratinocytes.