Definitions

Question 1

Loss of cohesion between individual keratinocytes with breakdown of desmosomes leading to round cells with a central nucleus that is rimmed by condensed eosinophilic cytoplasm

Answer 1

Acantholysis

Question 2

Increased thickness of the stratum spinosum

Answer 2

Acanthosis

Question 3

Individual programmed cell death leading to eosinophilic, shrunken cells

Answer 3

Apoptosis

Question 4

Intracellular oedema leading to swollen, eosinophilic cytoplasm, enlarged or condensed nuclei, loss of cohesion and vesicle formation

Answer 4

Ballooning degeneration

Question 5

Premature or abnormal keratinisation of individual keratinocytes leading to eosinophilic, shrunken cells with condensed, dark staining nuclei

Answer 5

Dyskeratosis

Question 6

Deposition of calcium salts as basophilic, amorphous, granular material along collagen fibrils

Answer 6

Dystrophic mineralisation

Question 7

Giant clumps of melanin found within melanocytes or hair shafts

Answer 7

Macromelanosomes

Question 8

Migration of inflammatory cells through the intercellular spaces of the epidermis

Answer 8

Exocytosis

Question 9

Dermal papillae devoid of attached epithelial cells that project into a vesicle or bulla

Answer 9

Festoons

Question 10

Deposition of amorphous eosinophilic material resembling fibrin in the walls of blood vessels

Answer 10

Fibrinoid degeneration/necrosis

Question 11

Formation and development of fibrous reactive tissue

Answer 11

Fibroplasia

Question 12

Inflammation of the hair follicle that has resulted in destruction of the follicular epithelium and release of luminal contents into the dermis

Answer 12

Furunculosis

Question 13

Relatively normal collagen that separates the epidermis from an underlying dermal alteration

Answer 13

Grenz zone

Question 14

Tumour-like malformation of an abnormal mixture of normal tissue elements or an abnormal single element (normal to location)

Answer 14

Hamartoma

Question 15

Inflammation of epitrichial (apocrine) sweat glands

Answer 15

Hidradenitis

Question 16

Focal, circular, concentric layers of squamous cells showing gradual keratinisation toward the centre

Answer 16

Keratin pearls

Question 17

Increased thickness of the stratrum corneum with no nuclei

Answer 17

Orthokeratotic hyperkeratosis

Question 18

Increased thickness of the stratum corneum with nucleated cells

Answer 18

Parakeratotic hyperkeratosis

Question 19

Increase in number of epidermal cells with even rete ridges

Answer 19

Regular or Psoriasiform hyperplasia

Question 20

Extreme, irregular epidermal hyperplasia with increased mitosis and branched or fused rete pegs

Answer 20

Pseudocarcinomatous hyperplasia

Question 21

Intracellular oedema restricted to the basal layer of the epidermis and outer root sheath with clear vacuoles within the keratinocytes

Answer 21

Hydropic degeneration

Question 22

Accumulation of dermal ground substance - granular, basophilic material that separates or thins collagen fibres

Answer 22

Mucinosis

Question 23

Small, desiccated accumulations of neutrophils in stratum corneum

Answer 23

Munro’s microabscess

Question 24

Loss of keratinocyte intercellular bridges, rounding of cells, normal-sized or swollen eosinophilic cytoplasm, pyknotic nucleus

Answer 24

Necrosis

Question 25

Projection of dermal papillae and epidermis above the surface of the skin

Answer 25

Papillomatosis

Question 26

Small, focal accumulation of abnormal lymphoid cells in the epidermis/follicular epithelium

Answer 26

Pautrier’s microabscess

Question 27

Free melanin granules within the subepidermal dermis and dermal macrophages (melanophages)

Answer 27

Pigmentary incontinence

Question 28

Severe intracellular oedema of epidermal cells, cells burst and result in multilocular intraepidermal vesicles whose septa are formed by resistant cell walls

Answer 28

Reticular degeneration

Question 29

Individual necrotic keratinocytes in the epidermis surrounded by lymphoid cells

Answer 29

Satellitosis

Question 30

End point of fibrosis – increased numbers of collagen fibres, thick hyalinised appearance, reduced numbers of fibroblasts

Answer 30

Sclerosis

Question 31

Epidermal widening of intercellular spaces with accentuation of intercellular bridges that may lead to intraepidermal/subepidermal vesicles

Answer 31

Spongiosis

Question 32

Whorl-like patterns of squamous cells with no atypia, dyskeratosis or central keratinisation

Answer 32

Squamous eddies

Question 33

Dermal papilla covered by 1-2 layers of epidermal cells that projects into the base of a vesicle/bulla

Answer 33

Villus

Question 34

What does coagulation necrosis look like?

Answer 34

Typical microscopic changes in coagulative necrosis become prominent in 4-12 hours, there is preservation of basic outline of injured cells along with denaturation of cellular proteins. There is increased eosinophilia due to denaturation of proteins, loss of normal basophilia imparted by RNA degeneration. Secondly, eosin stain has more affinity for denatured proteins.