W5 L7: TUMOURS OF SKIN

Question 1

What are the benign tumours of squamous cells?

Answer 1

• Squamous papilloma (Fibroepithelial polyp)
• Seborrheic Keratosis
• Acanthosis Nigricans
• Keratoacanthoma

Question 2

List the premalignant tumours of squamous cells

Answer 2

• Actinic Keratosis
• Carcinoma-in-situ (Bawen’s disease)

Question 3

List the malignant tumours of squmaous cells

Answer 3

• Invasive squamous cell carcinoma

Question 4

The features of squamous papilloma:

Answer 4

• Age: middle aged individuals
  -Race groups:
• Sites: Face, Neck, trunk, and intertriginous areas
• Appearance: Fleshy bag-like tumour attached by slender stalk
• Risk factors: obesity, diabetes pregnancy and intestinal polyposis
  Histology: fibrovascular core covered by benign epithelium

Question 5

The features of SEBORRHEIC KERATOSIS

Answer 5

• Age: middle aged individuals
• Race groups:
• Sites: Head, neck, Trunk, extremities
  *May occur in clusters on the face (dermatosis papulosa nigra)
• Appearance: Round, flat dark plaques with velvety granular surface
• Risk factors: Arises spontaneously (FGFR3 mutation)
• Histology: Exophytic and sharply demarcated epidermal thickening, variable melanin pigmentation, exuberant keratin production, horn cyst and invagination cysts

Question 6

The features of acanthosis nigricans

Answer 6

Age: childhood and adolscent

Site: Flexural areas of the body; back of the knees, groin, elbow, armpit

Appearance: Thick, velvety hyperpigmentation of the skin

Risk factors: FGFR3 gene mutation
-Endocrine abnormalities, diabetes, as part of rare congenital syndromes

Histology: Sharp epidermal and dermal papillary convulsions forming “valleys”,
hyperkeratosis, slight hyperpigmentation

Question 7

Features of keratoacanthoma

Answer 7

Appearance: Symmetrical, cup shaped papule with a central depression containing keratin debris

Aetiology:
Virus

Histology:
cells be having glassy cytoplasm, there’s hyperkeratinisation, presence of lymphocytes and eosinophils

Question 8

Features of premalignant tumours: ACTINIC KERATOSIS

Answer 8

• Age:
  -Race groups: Light skinned individuals
• Sites: Sun damaged skin
• Appearance: Tan-brown lesions usually > 1cm and may form cutaneous horns
• Risk factors: Occur in sun damaged skin and exhibit hyperkeratosis
• Histology: basal cytological atypia and basal hyperplasia, hyperkeratosis; parakeratosis;
  intercellular bridges present; solar elastosis

*Hyperkeratosis is a dermatological condition characterized by the thickening of the outer layer of the skin, known as the epidermis, due to an abnormal accumulation of keratin

Question 9

Which melanoma sees vertical growth?

Answer 9

nodular melanoma

Question 10

Which 3 melanomas see radial (horizontal) growth?

Answer 10

-Acral lentiginous melanoma
- Superficial spreading melanoma
- Lentigo maligna melanoma

Question 11

Name 2 types of tumours referred to as benign melanoctyic tumours

Answer 11

• Melanocytic naevus
• Blue naevus

Question 12

Which tumour is referred to as a pre-malignant melanocytic tumour?

Answer 12

Dysplastic naeveus

Question 13

Name 3 types reflecting progression of a melanocytic naveus or moles

Answer 13

• Junctional
• Compound
• Intradermal

Question 14

What are the population groups more prone to melanoma arising from sun exposure?

Answer 14

• Light skinned
• Those with poor tanning ability

Question 15

Population least affected by melanoma

Answer 15

Dark skinned and children

Question 16

What are the Risk factors to developing melanoma?

Answer 16

• UV,
• ionizing radiation,
• albinism,
• dysplastic naevus syndrome,
• xeroderma pigmentosum,
• giant congenital naevus

Question 17

Currently, what determines the type of melanoma according to the WHO?

Answer 17

The degree of sun exposure

Question 18

Prognostic factors in squamous cell carcinoma

Answer 18

o Correlates with depth of invasion
o Breslow tumour thickness
o Clark’s levels of tumour invasion
o Others: Ulceration, mitoses, necrosis, regression