Pathology Flashcards
Seborrhoeic keratosis
- What is it?
- Who is it common in and where on the body?
- How do the lesions appear?
- Pathological features?
- Benign proliferation of epidermal keratinocytes
- Very common in ageing/elderly skin
- Common on face, chest and back
- Stuck on appearance - greasy hyperkeratotic surface
- Epidermal acanthosis, hyperkeratosis, horn cysts
Eruptive appearance of many seborrhoeic lesions lesions in a short time period may indicate internal malignancy.
What sign is this?
Leser-Trelat sign
Very hyperplastic keratin layer and horn cysts.
This is the histology of which condition?
Seborrhoeic keratosis
How should you investigate seborrhoeic keratosis?
Curette and send for histology
Who is basal cell carcinoma common among?
- Sun exposed sites
- UK - middle aged and elderly
- Australia - younger age groups
What are the three main subtypes of basal cell carcinoma?
- Nodular
- Superficial
- Infiltrative (morphoeic)
How does a basal cell carcinoma develop?
Does it metastasize?
Can it kill?
- Basal cells sprout from epidermis
- Groups of cells invade dermis
- Peripheral palisading
- Mitoses and apoptoses very numerous
- Slow growing, locally destructive
Almost never metastasises
May kill by invading eye -> brain
What is the most severe type of basal cell carcinoma and why?
Infiltrative type
- Margins are poorly defined
- May spread along nerves
- Resection may be challenging
How does nodular basal cell carcinoma appear on histology?
Very well defined; nodules of basal cells which spread down into the dermis
What can superficial BCC mimic?
Eczema
How does infiltrative BCC show on histology?
Desmoplastic stroma
Give three common precursors of squamous cell carcinoma.
What do they have in common?
- Bowen’s disease – occurs especially on legs
- Actinic keratosis – little scaly things especially on head/neck
- Viral lesions - especially on anogenital skin
All show squamous dysplasia
Bowen’s disease
- What is it?
- Who gets it and where on the body?
- How does it appear?
- is it invasive?
- What can it mimic?
- This is squamous cell carcinoma in –situ
- Female excess – mostly presents on lower leg
- A well-defined, slowly enlarging, red scaly plaque with irregular border
- No dermal invasion
- Can be erythematous and hence mimic inflammatory conditions in some cases
Actinic keratosis
- Where on the body?
- Precursor of?
- What does histology show?
- Sun-exposed skin esp. scalp, face, hands
- Common precursor of invasive SCC
- Histology shows parakeratosis with moderate squamous dysplasia
What is Erythroplasia of Queryat
Which pathogen is it associated with?
Penile Bowen’s disease
Associated with HPV
What are the most common sites for SCC?
What are some less common sites?
Elderly, sun exposed sites (face, ears, dorsal hands)
Occasionally arises
- Chronic leg ulcers e.g. stasis ulcers
- Sites of burns; sinuses e.g. chronic osteomyelitis
- Chronic lupus vulgaris
How does SCC tend to behave?
- Generally good prognosis
- Locally invasive
- Low but definite risk of metastasis
What are some adverse prognostic features of SCC?
- Thickness > 4mm and poor differentiation
- Lymphatic / vascular space invasion
- Perineural spread
- Specific sites poorer prognosis - scalp, ear, nose