40 BASICS
TABLE 4.2. (Continued)
Hydropic degeneration Vacuolar damage to the stratum basale; frequently seen with discoid lupus
erythematosus
Hyper- and hypogranulosis Denotes thickness of stratum granulosum (e.g., areas of lichenification
reveal hypergranulosis)
Hyperkeratosis Increased thickness of stratum corneum layer of epidermis; divided into
orthokeratosis (nuclei lost) and parakeratosis (nuclei retained); assists in
identifying an etiology (e.g., zinc-responsive dermatosis is characterized by
parakeratosis)
Hypomelanosis Decrease in pigment; as seen in vitiligo
Melanosis Hyperpigmentation; seen in chronic inflammation
Microabscess, eosinophilic Seen in EGC, allergy, pemphigus complex, Malassezia, eosinophilic
folliculitis
Microabscess, Munro’s Accumulation of neutrophils within or below the stratum corneum; often
seen in psoriasiform lichenoid dermatosis of springers
Microabscess, Pautrier’s Accumulation of abnormal lymphoid cells; often seen in epitheliotropic
lymphoma
Microabscess, spongiform Accumulation of neutrophils within stratum spinosum often seen with
superficial suppurative necrolytic dermatitis of schnauzers
Mucinosis Increased amounts of amorphous basophilic material in the dermis;
characteristic of normal skin in the shar-pei dog and in hypothyroidism
Necrolysis Epidermal coagulative necrosis with no dermal involvement and minimal
inflammation; often seen with TEN and thermal burns
Papillomatosis Epidermal proliferation due to papilloma virus infection, often exophytic;
may be endophytic
Pigmentary incontinence Melanin pigment dropped from the epidermis into the dermis and
phagocytized by macrophages; often seen with DLE
Reticular degeneration Multilocular intraepidermal edema with keratinocyte swelling; often seen
with superficial necrolytic dermatitis/hepatocutaneous syndrome
Satellitosis Cytotoxic lymphocytes surrounding an apoptotic cell; indicates
cell-mediated immune response
Spongiosis Epidermal intercellular edema
Sclerosis Scar formation
Vacuolar degeneration Intracellular edema
DLE, discoid lupus erythematosus; EGC, eosinophilic granuloma complex; RBC, red blood cell; TEN, toxic epidermal
necrolysis; WBC, white blood cell.