dermpath nodular Flashcards
The Language of Skin:
Papule
- histo term?
- A papule is a small (<1cm) elevation of the skin that is palpable as a solid mass
- Histological term: NODULE
The Language of Skin: Nodule
- histo term
- A nodule is a circumscribed, solid elevation in the skin, greater than 1 cm in diameter, and extending deeper into the dermis. Usually due to accumulation of inflammatory cells, neoplastic cells or crystalline material in dermis and subcutis
- Histological term: NODULE
Language of Skin: Tumour definition
- histo term
- A Tumour is a large mass that typically involves
dermis and subcutis. - These are usually neoplastic, but in its pure sense, the term “tumor” includes inflammatory lesions, usually granulomatous lesions.
- Histological term: MASS, TUMOUR, NODULE
Nodular skin diseases
- what do they contain?
- how are they defined? dermpath patterns?
◼ Nodules have extra tissue – inflammatory cells
◼ Defined by Target of inflammation
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◼ Follicular targeting or alopecia
> DERMPATH pattern: 3. FOLLICULITIS, FURUNCULOSIS, SEBACEOUS ADENITIS
◼ In dermis but no follicular targeting
> DERMPATH pattern: 4. NODULAR to DIFFUSE DERMATITIS
◼ Deep nodules
> DERMPATH pattern: 5. PANNICULITIS
Nodular skin disease
- what is the best sample?
- broad categories of disease
◼ Biopsy – take a whole nodule
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Infectious
◼ Cell type (neutrophil, eosinophil, lymphocytes, histiocytes) helps with cause
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Noninfectious
◼ Immune mediated = immune modulatory therapy
DERMPATH pattern:
3. FOLLICULITIS, FURUNCULOSIS AND SEBACEOUS ADENITIS
- what is it?
- causes for each of these?
Inflammatory disease targeting hair follicles or part of hair follicle
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Folliculitis, furunculosis
* Infectious
> Bacteria
> Ringworm (Dermatophytes)
> Demodex
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* Non-infectious
> Eosinophilic
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Sebaceous adenitis
* Breed associated
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Alopecia areata
Adnexa of skin
◼ Hair follicle
> Infundibulum
> Isthmus
> Inferior
◼ Sebaceous glands
◼ Apocrine glands
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◼ Eccrine glands
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◼ Anal sac and apocrine gland
◼ Perianal (hepatoid) glands
◼ ? mammary glands
DERMPATH pattern: Folliculitis - types, how they arise
Luminal folliculitis
◼ Inflammation targets the center and contents of the follicle.
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Mural folliculitis
◼ Inflammation targets the wall of the follicles
◼ Similar diseases to vesiculopustular diseases of epidermis
Folliculitis - types, infectious causes
Types
◼ Luminal (within lumen of follicle)
◼ Mural (within wall of follicle)
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Causes - Infectious
◼ Bacteria
◼ Dermatophyte
◼ Demodex
Furunculosis - what is it?
- Nodular inflammatory reaction following rupture of hair follicle.
- Usually an exaggerated reaction to luminal folliculitis.
Sebaceous adenitis - what is it?
- Specific targeting of the sebaceous glands.
- Type of mural folliculitis
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possible effects - nodular skin disease, scaling skin disease, alopecia
DERMPATH pattern: Sebaceous adenitis (SA)
- what does it cause?
- breeds?
- what happens?
◼ Causes a scaling disease clinically
◼ Breed associated SA
> Standard poodles
> Vizsla
◼ Sporadic SA
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◼ Lack of sebum
> Dry skin
> Hyperkeratosis – scaling, seborrhea
DERMPATH pattern:
4. NODULAR and DIFFUSE DERMATITIS
- causes, broadly
◼ Infectious
◼ Sterile
NODULAR AND DIFFUSE DERMATITIS
- Subdivide according to type of inflammation:
- Neutrophilic
- Eosinophilic
- Granulomatous
- Pyogranulomatous
- Lymphocytic Plasmacytic
- Histiocytic
- NODULAR AND DIFFUSE DERMATITIS
- infectious causes
- lab tests
Infectious
◼ Bacteria - abscess
◼ Mycobacteria, Nocardia
◼ Fungi – Blastomyces (rarely dermatophytes)
◼ Protozoa – Leishmania
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Laboratory tests
◼ Pathologist will do special stains on the biopsy sections
◼ Send tissue samples for culture
◼ Serology if appropriate
