INFECTIONS AND INFESTATIONS Flashcards
Patterns for syphilis
Psoriasiform +lichenoid
What are the features of syphilis
- Predominant infiltrate: plasma cell (has eccentric, clock-face nucleus)
- Endothelial swelling
- Warthin-Starry: stains spirochetes
stain for spirochetes
Warthin-Starry: stains spirochetes
features of TB VERRUCOSA CUTIS
Scanty focal granuloma, psoriasiform + lichenoid AFB typically negative
features of LUPUS VULGARIS
More organized granuloma, caseation necrosis, variable epidermal changes AFB +/-
features of scrofuloderma
Mixed inflammation, granuloma, marked fibrosis, caseation necrosis AFB +/-
hallmark of cutaneous TB
TUBERCULOID GRANULOMA
Identify the type of granuloma
Tuberculoid granuloma
- epithelioid histiocytes with surrounding mantle of lymphocytes
identify the pointed structure
Langhans giant cells - granuloma with multinucleated giant cells
Tuberculoid Caseating Granuloma
- Caseation: focal eosinophilic area od necrotic collagen surrounded by rim of histiocytes
Caseation necrosis
Pattern of cutaneous tuberculosis
GRANULOMATOUS
TVC: psoriasiform + Lichenoid
Scrofuloderma: diffuse
pattern of erythema induratum
Predominantly lobular panniculitis with vasculitis
Features:
- Histiocytes + mutinucleated giant cells
- Mixed cell infiltrate
- Small to medium-sized vasculitis
pattern of tuberculoid leprosy
Granulomatous - nodular (superficial and deep)
pattern of lepromatous leprosy
Granulomatous - diffuse (superficial and deep)
Identify spectrum of leprosy
TUBERCULOID LEPROSY
- (-) grenz zone
- Well-organized granulomas (may be elongated/linear)
Identify spectrum of leprosy
LEPROMATOUS LEPROSY
- (+) grenz zone
- diffuse foamy histiocytes
Tuberculoid: nodular (tight, ‘stretched-out’ granulomas)
Tuberculoid: epithelioid +/- giant cells
Lepromatous: foamy + globi
Identify spectrum of leprosy
BORDERLINE TUBERCULOID
- Focal/incomplete grenz zone
- Epithelioid histiocytes +/- giant cells
Identify spectrum of leprosy
BORDERLINE BORDERLINE
- Poorly organized epithelioid granulomas
- Epithelioid + Foamy histiocytes
Identify spectrum of leprosy
BORDERLINE LEPROMATOUS
- Poorly to moderately defined, loose granulomas
- Epithelioid < Foamy histiocytes
Pattern of Erythema Nodosum Leprosum
Predominantly lobular panniculitis with vasculitis Superficial and deep, nodular and diffuse infiltrates
Feature: Diffuse infiltrates of neutrophils
HERPES SIMPLEX/VARICELLA
Intraepidermal blister
- ballooning of keratinocytes (INTRACELLULAR EDEMA)
- acantholysis
✓ Pale necrotic keratinocytes
✓ Steel gray nuclei
✓ Molding and margination of nuclear chromatin
✓ Multinucleation of keratinocytes
✓ Ground glass inclusions
✓ +/- leukocytoclastic vasculitis
MOLLUSCUM CONTAGIOSUM
Endophytic bulbous acanthosis / Crateriform invagination
Henderson-Patterson bodies (intracytoplasmic inclusion bodies)
VERRUCA VULGARIS
Papillomatous architecture
Inward bending of rete ridges
Features:
- Koilocytes: vacuolated cells with basophilic nuclei surrounded by a clear halo
- Hyperkeratosis with tiers of parakeratosis
- Hypergranulosis with enlarged keratohyaline granules
- Dilated vessels in the dermis
Dermatophytosis
DERMATOPHYTOSIS
Superficial perivascular; Spongiosis
- Sandwich sign: PAS positive hyphae in the parakeratotic stratum corneum
- Subcorneal pustule as a clue
TINEA VERSICOLOR
Pattern/s: Superficial perivascular dermatitis / invisible dermatosis
- Intracorneal hyphae (spaghetti) and spores (meatballs)
MAJOCCHI’S GRANULOMA
Granulomatous; Periinfundibulitis, perifolliculitis + neutrophilic microabscess
- Spores and hyphae within the dermis and follicular infundibulum
- Mixed cell infiltrate
+/- ruptured follicle
CHROMOMYCOSIS
Pattern/s: Granulomatous + Pseudoepitheliomatous hyperplasia +Suppurative
- Round, brown, thick-walled yeast forms: Medlar bodies/ sclerotic bodies (“copper pennies”)
- Neutrophilic abscesses within epidermis
EUMYCETOMA
- Granulomatous, nodular to diffuse
- Granules
- Diffuse mixed cell infiltrate
- Focal neutrophilic abscesses
- (+/-) giant cells
- Splendore-hoeppli phenomenon: eosinophilic rim surrounding granule
CRYPTOCOCCOSIS
Pattern/s: Granulomatous, diffuse; “soap bubble appearance”; Suppurative
- Mucoid dermal infiltrate
- Giant cells
- Spherical yeast with mucoid capsule
- STAINS:
- PAS highlights cell wall with red
- Yeast cells stain black with GMS
- Capsule stains with alcian blue and mucicarmine
AMASTIGOTES OF LEISHMANIASIS
Pattern: Granulomatous
- Histiocytes with amastigotes (Leishman-Donovan bodies)
- Dense dermal infiltrate of lymphocytes, histiocytes, plasma cells
- Giemsa stain: highlights organism
SCABIES
-Spongiosis; Epidermal hyperplasia
- Eosinophils
- Dense diffuse and nodular mixed infiltrate
- Eggs, mites or sycbala (eggs) in the stratum corneum
