Introduction Cutaneous deposits are a heterogeneous group of substances that are not normal constituents of the skin. They are laid down, usually in the dermis, in a variety of different circumstances. There are five broad categories of deposits ( Table…
Introduction The mucinoses are a diverse group of disorders that have in common the deposition of basophilic, finely granular, and stringy material (mucin) in the connective tissues of the dermis (dermal mucinoses), in the pilosebaceous follicles (follicular mucinoses), or in…
Introduction Normal elastic tissue Elastic fibers are the important resilient component of mammalian connective tissue, and their presence is necessary for the proper structure and function of the cardiovascular, pulmonary, and intestinal systems. Their structural role is to endow tissues…
Introduction Collagen is the major structural constituent of mammalian connective tissues. It accounts for well over 70% of the dry weight of the skin. There are at least 10 genetically distinct types of collagen, and it is the relative content…
Introduction This chapter deals with the various disorders of cutaneous pigmentation, excluding those entities in which there is an obvious lentiginous proliferation of melanocytes in sections stained with hematoxylin and eosin (H&E); it also excludes tumors of the nevus cell–melanocyte…
Introduction This chapter deals with a heterogeneous group of diseases in which an abnormality of maturation, of keratinization, or of structural integrity of the epidermis is present. Many advances have been made in the past decade in our understanding of…
Introduction Cutaneous blood supply The skin is supplied by small segmental arteries that may reach the skin directly or after supplying the underlying muscle and soft tissues en route. These vessels branch to supply the subcutis with a meshwork of…
Introduction The granulomatous reaction pattern is defined as a distinctive inflammatory pattern characterized by the presence of granulomas. Granulomas are relatively discrete collections of histiocytes or epithelioid histiocytes with variable numbers of admixed multinucleate giant cells of varying types and…
Introduction The vesiculobullous reaction pattern is characterized by the presence of vesicles or bullae at any level within the epidermis or at the dermoepidermal junction. Pustules, which are vesicles or bullae containing numerous neutrophils or eosinophils, are included in this…
Introduction The spongiotic tissue reaction is characterized by the presence of intraepidermal and intercellular edema (spongiosis) ( Fig. 6.1 ). It is recognized by the widened intercellular spaces between keratinocytes, with elongation of the intercellular bridges ( Fig. 6.2 ).…