Skin - non tumour

Question 1

granulomas

Answer 1

necrobiotic (x4)

infection: bacterial (incl TB etc) fungal, parasites (eg leishmaniasis

drugs

foreign body

sarcoid

Crohn disease

Question 2

panniculitis

Answer 2

septal: erythema nodosum, necrobiosis lipoidica, infection
lobular: erythema induratum, lupus, T cell lymphoma, pancreatic fat necrosis, fat necrosis of newborn

Question 3

erythema nodosum - morphology and DDX

Answer 3

neutrophils, lymphocytes and giant cells

DDX: infection (TB, syphilis, fungi), necrobiosis lipoidica

Question 4

dermal hypersensitivity reaction - morphology and causes

Answer 4

superfical or superficial and deep perivascular inflammation, lymphocytes and eosinophils

Causes: drugs, urticaria, organisms (arthropod, fungus)

Question 5

psoriasiform dermatitis

Answer 5

psoriasis (neuts in epidermis, no granular layer)

pityriasis rubra pilaris -K

dermatophytosis (PAS) - F

lichen simplex chronicus (chronic spongiotic dermatitis) - C

also stasis dermatitis (overlaps with spongiotic pattern)

Question 6

subepithelial bullous dermatitis, with eosinophils

Answer 6

bullous pemphigoid (linear IgG), pemphigus gestationis (linear C3), drugs

Question 7

subepithelial bullous dermatitis, with neutrophils

Answer 7

dermatitis herpetiformis (granular IgA papillary dermis), linear IgA disease, bullous pemphigoid (linear IgG)

Question 8

subepithelial bullous dermatitis, with lymphocytes

Answer 8

bullous lupus erythematosus

Question 9

subepithelial bullous dermatitis, with no inflammation

Answer 9

epidermolysis bullosa (linear IgG), porphyria cutanea tarda (festooned dermal papillae in blister), drugs

Question 10

intraepidermal bullous dermatitis

Answer 10

pemphigus: vulgaris, paraneoplastic (eosinophils)

Hailey-Hailey/benign familial pemphigus (intertriginous, ‘dilapidated brick-wall’, minimal inflammation)

Darier (back/neck/chest, corps ronds and grains, dermal lymphocytes)

Grover/transient acantholytic dermatosis (old men, itchy back and chest, sun damage)

Question 11

interface dermatitis, lichenoid

Answer 11

lichen planus (civatte and colloid bodies, no parakeratosis, only few eosinophils)

lichenoid drug reaction (eosinophils, parakeratosis)

Question 12

interface dermatitis, vacuolar

Answer 12

erythema multiforme (viral or medication)

Steven-Johnson/TEN (clinical, usu medication related)

fixed drug eruption (clinical, eosinophils)

lupus erythematosus

GVHD (clinical, lymphs in epidermis)

secondary syphilis (plasma cells)

Question 13

GVHD clinical triad

Answer 13

skin lesions

hepatic dysfunction

diarrhoea

Question 14

necrobiotic granulomas (4)

Answer 14

granuloma annulare, necrobiosis lipoidica, rheumatoid nodule, necrobiotic xanthogranuloma

Question 15

leukocytoclastic vasculitis - morphology

Answer 15

neutrophils, fibrin, karyorrhectic debris, extravasated RBCs

Question 16

leukocytoclastic vasculitis - causes

Answer 16

immune: HSP (IgA), SLE, RA, cryoglobulinaemia

pauci-immune: Wegeners (c-ANCA), Churg-Strauss (p-ANCA), microscopic polyangiitis (p-ANCA)

drugs

infection

malignancy

Question 17

eosinophils

Answer 17

infection: dermatophytosis, scabies, arthropod bite
inflammatory: dermatitis, pemphigus vulgaris, bullous pemphigoid, Churg-Strauss
neoplastic: epithelioid haemangioma, LCH, T cell/Hodgkin lymphoma, myeloid sarcoma

Question 18

neutrophils (10)

Answer 18

PALLID SHIPS

pustular psoriasis

AGEP

LCV

linear IgA disease

drugs

subcorneal pustular dermatosis

dermatitis herpeteformis

infection

pyoderma gangrenosum

Sweet’s

Question 19

superficial and deep lymphocytes

Answer 19

lupus

Sweets

lymphomatoid papulosis

arthropod bite