Histopathology COPY Flashcards
What are the patterns of the stratum corneum that can be seen on histopathology?
Basket weave (lacy) **normal
Lamellar/laminated (condensed, but separates)
Compact (dense, does not separate)
Parakeratotic (retained nuclei) versus normal orthokeratotic
What is parakeratosis indicate on histopathology?
Incomplete keratinocyte maturation or a defect in filaggrin conversion
Young Cocker spaniel
Epidermal hyperplasia (mild to papillated
Alternating vertical tiers of ortho- and parakeratosis)
Follicular plugging and follicular ostia w/ parakeratotic caps/epaulettes
Suggestive of primary seborrhea (ddx: allergy, Vit A-responsive)
10 yr MC Cocker spaniel with alopecic plaques and follicular casts
Severe follicular keratosis
Distended ostia with plug protrusion (follicular fronds)
Suggestive of vitamin A-responsive dermatosis
What do you expect to see on histopathology of non-epidermolytic ichthyosis?
Lamellar / laminated to compact orthohyperkeratosis (mild to severe)
- “filo dough effect”
- Goldens: abnormal keratin rather than ↑
- Focal parakeratosis can happen
Perinuclear clear spaces in granular layer
What do you expect to see on histopathology of epidermolytic ichthyosis?
Lamellar / laminated to compact orthohyperkeratosis (mild to severe)
Lysis of upper epidermal layers
Hypergranulosis with abnormal keratohyalin granules
Diffuse keratinocyte ballooning
What form of ichthyosis is this?
Non-epidermolytic
What form of ichthyosis is this?
Epidermolytic
What stains can be used to highlight the BMZ?
PAS - purplish
Which autoimmune subepidermal blistering diseases show dermal positioning of collagen IV/PAS staining of the blister using anti-collagen IV IHC or IF or PAS staining (patient’s biopsy sections)?
BP, PG, JEBA
Which autoimmune subepidermal blistering diseases show mixed positioning of collagen IV/PAS staining of the blister using anti-collagen IV IHC or IF or PAS staining (patient’s biopsy sections)?
JEBA
Which autoimmune subepidermal blistering diseases show epidermal positioning of collagen IV/PAS staining of the blister using anti-collagen IV IHC or IF or PAS staining (patient’s biopsy sections)?
EBA, bullous SLE
What are the advantages and disadvantages of indirect immunofluorescence?
Advantages
- Secondary signals may be amplified
- A few labeled secondaries can detect many primaries
- Greater flexibility
- Easy to change colors
Disadvantages
- Two-step staining process
- potential cross reactivity
- finding labeled primary antibody which is more difficult to get especially for multiple labeling experiments
Salt split skin, staining on roof
BP, PG
Salt split skin, staining on floor
EBA, JEBA, mixed, bullous SLE
Which AISBD is this most consistent with?
Mucous membrane pemphigoid
What can be used to differentiate MMP from EBA?
A positive PAS staining and/or anti-collagen IV IHC should label the dermal side (floor) of the blister in biopsies of MMP, not EBA
Which AISBD is this most consistent with?
Bullous pemphigoid, dog
What are the histopathologic findings associated with bullous pemphigoid?
Level of split: lamina lucida
Histopathology: subepidermal vesiculation +/- eos, neuts, fibrin
- Eos in the superficial dermis
- IgG, IgM, or IgA and/or complement deposited at the BMZ
Which AISBD is this most consistent with?
Bullous pemphigoid, horse
Which AISBD is this most consistent with?
EBA
What are the histopathologic findings associated with epidermolysis bullosa aquisita (EBA)?
Level of split: sublamina densa
Histopathology:
- subepidermal vesiculation with no to variable amounts of neutrophilic inflammation +/- fibrin or minor hemorrhage
- vacuolation and rowing of neutrophils and/or histiocytes occurs just below the BMZ
- Superficial dermal perivascular to interstitial dermatitis
This is a biopsy sample from a young Yucatan mini-pig. Which AISBD is this most consistent with?
BP