Small Animal Dermatology, 3rd edition

(Tina Sui) #1

CHAPTER 4 OBTAINING A DIAGNOSTIC BIOPSY 39


TABLE 4.2.Common Histopathologic Terminology


Term Meaning


Acanthosis Increased thickness of epidermis (epidermal hyperplasia); often noted with
chronic inflammation


Acantholysis Loss of adhesion of keratinocytes (acantholytic keratinocytes); often due to
autoimmune diseases such as pemphigus foliaceus; may also be seen in
inflammatory disease


Amyloid Hyaline, amorphous, eosinophilic material


Apoptosis Individual premature keratinocyte death


Atrophy, epidermal Thin epidermis; often associated with corticosteroid use


Ballooning degeneration Koilocytosis, swollen cytoplasm without vacuolization; characteristic of
viral infection


Bullae Fluid-filled acellular spaces within or below the epidermis (vesicles are
smaller bulla)


Cholesterol clefts Appear as clear spicule-shaped spaces; often seen with xanthomatosis,
panniculitis, and ruptured follicular cysts


Civatte bodies Apoptotic cells in the stratum basale of the epidermis


Clefts Slit-like spaces within the epidermis or dermoepidermal junction; caused by
acantholysis, hydropic degeneration of basal cells, or processing artifacts


Collagenolysis Denatured collagen, homogeneous, eosinophilic, often attracts
mineralization


Crust Surface accumulation of epidermal cells, serum proteins, RBCs, WBCs


Dermoepidermal junction Interface between epidermis and dermis


Dell Small depression on the surface of the epidermis


Desmoplasia Fibroplasia induced by neoplasia


Diapedesis RBCs within the intercellular spaces of the epidermis; implies loss of
vascular integrity


Dyskeratosis Premature faulty keratinization; may be seen with neoplasia or
keratinization disorders


Dystrophic mineralization Deposits of calcium along collagen fibers


Exocytosis Migration of inflammatory cells, RBCs, or both into intercellular spaces


Fibroplasia Increased amounts of fibrous tissue


Fibrosis Advanced fibroplasia, thick parallel strands of collagen; characteristic of
acral lick dermatitis


Flame figures Areas of altered collagen surrounded by eosinophilic material, see
collagenolysis; often noted with eosinophilic granulomas, also called
excessive trichilemmal keratinization


Grenz zone Marginal zone of collagen that separates the epidermis from an underlying
dermal alteration; often seen in neoplastic and granulomatous disorders


(Cont.)
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