Cancer Flashcards
What is melanoma?
Melanoma is a type of malignant cancer that arises from the melanocyte layer of the skin, normally situated at the basal layer of the epidermis (inner most layer).
Melanoma occurs when melanocytic stem cells undergo a …. and ….
genetic transformation and proliferate uncontrollably.
What do melanocytes produce?
Melanin
Melanin function
Melanin is a protein that helps protect against harmful ultraviolet radiation exposure.
Why is damage caused by UV exposure more likely in white skin compared to dark-brown or black skin?
Melanocytes are found in equal numbers in different skin tones. However, darker skin produces more melanin.
In situ meaning
The tumour is confined to the epidermis
Invasive meaning
The tumour has spread into the dermis
Metastatic meaning
The tumour has spread to other tissues
medical name for moles
benign melanocytic naevi
medical name for freckles
lentigines and phelides
When melanocytes grow in a non-cancerous way, they result in…
moles and freckles
What are the 4 common subtypes of melanoma?
Superficial spreading melanoma (most common), nodular melanoma, lentigo melanoma, acral lentiginous melanoma.
Risk factors of melanoma
History of skin cancer, melanoma, or atypical naevi
Family history of melanoma
Pale skin (Fitzpatrick skin type I and II)
Red or light-coloured hair
High freckle density
Light coloured eyes
History of sunburn
Sun exposure or tanning bed exposure
Large amounts of moles
Increasing age
Immunosuppression
Outdoor occupation
Genetic syndromes with skin cancer predisposition (for example, xeroderma pigmentosum)
What is the name for a melanoma with no pigment?
Amelanotic melanoma
What is the ABCDE criteria that is used to describe features that most melanomas have?
Asymmetrical shape
Border irregularity, including poorly defined margins
Colour change and variation
Diameter of the mole (most melanomas are >6mm)
Evolving (such as changing in size, shape or colour)
What is seborrhoeic ketatoses?
A common and benign class of lesion that can score highly on the ABCDE criteria are seborrhoeic keratoses (aka seborrhoeic warts).
Dermoscopic features of melanomas
-atypical network (white or pigmented)
-aggregated black or brown dots and globules
-features specific to the site of the melanoma (e.g. parallel pattern on palms and soles).
What is Breslow thickness?
Measures the thickness of invasive melanoma in millimetres from the granular cell layer to the deepest tumour cell.
What does a sentinel lymph node biopsy test for?
Spread of cancer
What is the medical management for malignant melanoma?
-targeted therapy such dabrafenib and vemurafenib may be used in patients with BRAF V600 mutation-positivity
- immunotherapy such as nivolumab plus ipilimumab
-chemotherapy for advanced melanoma not responsive to treatment
All suspicious pigmented lesions should undergo…
excisional biopsy for histology
What is the most common type of cancer in the world?
Basal cell carcinoma
What is basal cell carcinoma?
It is a non-melanoma form of skin cancer that develops very slowly in the upper layers of the skin and rarely metastasises.
What are the 3 layers of the skin?
The epidermis: the thin outer portion of the skin made up of the inner basal layer, the prickle cell layer, the granule cell layer and the keratinised squamous layer (Figure 1)
The dermis: the thicker inner portion of the skin which consists of connective tissue and contains nerves, vessels and sweat glands
The hypodermis: the innermost layer that fuses with the dermis and consists of adipose tissue and sweat glands.
BCCs develop from mutations, usually in the … and … genes affecting the …. layer
BCCs develop from mutations, usually in the PTCH and TP53 genes, affecting the basal cell layer of the epidermis.
Risk factors for the development of BCC
Exposure to UV radiation, especially acute intermittent exposure at a young age
Fair skin prone to sunburn that does not tan easily
Ionising radiation
Repeated micro-injuries
Scars/chronic ulcers
Prolonged exposure to chemical agents (i.e. arsenic)
Gorlin syndrome
Immunosuppression
History of skin cancer
what 3 main types can BCCs be categorised into?
nodular, superficial and morpheaform (aka sclerosing or infiltrating)
also pigmented BCC
Common histological findings of all BCCs
Basophilic aggregations of basaloid keratinocytes with large nuclei and scant cytoplasm
Clefts of tumour tissue
Peripheral palisading of nuclei
Apoptotic cells
what is the most common type of BCC?
nodular
management options for BCC
surgical excision, ED&C (electrodesiccation and curretage), topical treatments (5-fluorouracil) , cryotherapy and photodynamic therapy
