Skin

Question 1

GENERAL
Layers of skin?
Terminology

Answer 1

• Stratum corneum, Str. granulosum, Str. spinosum, Str. basale (melanocytes)
• Langerhans cells, Merkel’s cells
• Dermis - adnexa
• Tela subcutanea (subcutis) - mainly adipose tissue

Hyperkeratosis, parakeratosis, dyskeratosis, acanthosis, papillomatosis, acantholysis, spongiosis

Question 2

GENERAL

1. AI diseases?
2. Acute inflammmations?
3. Chronic inflammations?
4. Bacterial?
5. Viral?
6. Fungal?

Answer 2

1. Pemphigus vulgaris, Pemphigoid
2. Eczema?, urticaria, blisters
3. Psoriasis (Lupenka), Lichen Planus
4. Staph, strep: superficial = impetigo, furuncle, carbuncle
5. HSV = labial, genial warts, HPV = warts/verruca, Herpes Zoster, Molluscum contagiosum = bumps with notches
6. Superficial - ‘Tinea’ .. capititis, corporis ..etc.

Vesicular (bullous), (blisters):
- Intraepidermal blisters - via ballooning/ancatholysis/spongiosis
- Subepidermal blisters - lifts up entire dermis up e.g. pemphigoid
clear fluid –> blister, pus –> pustule

NB. only real true fibroma = ovarian fibroma
Others called fibromas are reactive lesions, not true ones.

Question 3

Q54.

BNG LESIONS

Answer 3

1. Seborrheic keratosis :
   - old, middle aged people, spontaneous
   - maybe fibroblast growth factor receptor 3 mutation
   - variable melanin pigmentation
   - Lesser-trelat sign (underlying Ca esp. GIT Ca)
   macro - raised discolored plaques, stuck-on, waxy appearance
   micro - hyperkeratosis,keratin pseudocysts/pearls (w./wo some papillae protruding into dermis)
2. Actinic keratosis
   - skin dysplasia due to chronic sun exposure
   - hyperkeratosis, p53 mutation
   - pre-mlg, SCC precursor
   - other features: solar elastosis (dermis), parakeratosis, atypia - cytological, inflammation, not full thinckness atypia (SPAIN)
3. Epidermoid cysts - trauma cause cysts of epidermis filled with keratin and sebacious material.
4. Retention cysts (blocks ducts)
5. Condyloma accuminatum - HPV, genital warts, sq cell papilloma, koilocytes…

Question 4

Q54.

SQUAMOUS CELL CARCINOMA (EPIDERMOID /SPINDLE CELL CARCINOMA)

BASAL CELL CARCINOMA/ BASALIOMA

NB. Keratoacanthoma = well-differentiated SCC that develops rapidly and regresses spontaneously as a cup shaped tu filled with keratin debris

Answer 4

Squamous Cell Ca
- elderly (more common in men)
- Sun/UV exposure (DNA damage), carcinogens (tars, oils), chronic inflammations, irritation (burn scars, chronic ulcers), ionizing radiation, xerdoerma pigmentosum, immunosuppression, albinism etc.
- Arises from str. spinosum
- carcinoma in situ, ‘Bowen’s disease’, rarely metastasize <5%, if beyond BM –> true invasive SCC
- Decades to develop, may arise from precancerous lesions - actininc keratosis
macro = hyperpigmented/depigmented spots, slow growing sharply defined red plaques/ulcers with elevated margins
- light neoplastic cells
micro = hyperkeratosis
Two types = keratinizing (better prognosis), non-keratanizing (poor)
- mostly lymphogenic spread if do (better prog)
- Resection

2. Basal Cell Ca –> most common human cancer!!
   - UV light, face/upper body (upper lip)
   - areas with hair follicles
   macro = elevated nodule with central ulcer sur. by dilated blood vessels, pearl white shiny appearance
   - neoplastic cells are dark
   micro = solid - peripheral palisading, cystic - also has post-necrotic center
   - no metastasis but can be locally aggressive and infiltrate into dermis, if too deep can invade bone, orbit, skull –> meningitis (death)
   - resection - can recur

Question 5

Q55.

PIGMENTED NEVI ‘mole’

Answer 5

Congenital or acquired neoplasms of melanocytes
(flat/ raised papules w. symmetry, sharp bordersm uniform colour, small diameter <6mm) various sizes, colours etc.
1. Common nevus - junctional (children), compound (dangerous), intradermal (adults, fully matured nevus, fine)
2. Dysplastic nevi (often multiple, dif sizes)
familial or sporadic (most de novo), mainly compound nevi, abnormal growth and fusion of nests, may replace normal basal cell layer –> lentigionous hyperplasia, atypia, sparse ly infiltrate, loss of melanin w pahgocytosis & fibrosis around nests.
usu. larger that other nevi, multiple, flat to raised, various pigmentation, irreg borders, tendency on sun exposed skin…
3. Hab nevi - brown nevus with depigmented rim
4. Blue nevus - looks bluish due to deep into skin
5. Spitz nevus - young people, face, bng
6. Giant nevus - inherited, present at birth, often genital, inguinal or buttocks- swimsuit nevus

• swinsuit nevus and dysplatic nevus = precancerous, signs of transformation –> darkening, pain, ulceration, bleeding

Question 6

Q55.

MALIGNANT MELANOMA

Answer 6

FINAL NOTES AND SHEET

• features
• types/variants
• ABCDE
• Staging - Clark (depth) and Breslaw (thickness)

NB. Lentigo malignant = also ‘Hutchinson freckle’ (or Dubreillh disease). Precancerous, elderly women, best prognosis. Like a Ca in situ