Skin Cancers Flashcards
What are 3 examples of skin cancers?
- Basal cell
- squamous cell
- melanoma
What are 3 examples of skin cancers?
- Basal cell
- squamous cell
- melanoma
What is basal cell carcinoma (BCC)?
what / where does it arise from?
a slow-growing and locally-invasive skin cancer that arises from the pluripotent cells of the stratum basale layer of the epidermis.
How common is BCC compared to other skin cancers? How likely is it to metastasise?
- MOST COMMON skin cancer
- LEAST likely to metastasise
- lifetime risk of 23-39% in caucasians
RF for BCC?
- long-term UV exposure i.e. childhood sunburn
- UVA therapy for psoriasis
- Fitzpatrick type 1 skin
- immunosuppression (e.g. transplant patients have a 10-fold increased risk)
- Genetic syndromes (such as Xeroderma Pigmentosa or Gorlin syndrome)
UV exposure leads to genetic mutations in DNA (specifically on the p53 tumour suppressor )
Clincial features of BCC
where?
how present? charachter? onset? any other skin symptoms ?
- on sun-exposed areas of the head and neck, with the remainder mainly occurring on the trunk or lower limbs.
- small slow-growing lesions
- raised pearly edges
- evident telangiectasia.
Other symptoms:
* Initially - no
* IF LEFT -pain, bleeding, and ulceration, or subsequent local invasion into surrounding tissues.
Subtypes of BCC?
changes how they present
- Nodular
* most common 50-60%
* i.e. pink pearly nodule with talangiectasia
* can ulcerate / crusty - Superficial 10-15%
* erythematous scaly plaques with a thread like border
* may ulcerate / bleed - Morphoeic
- Basosquamous
Differentials for BCC?
- Trichoepithelioma ( rare benign tumour of the hair follicle)
- Keratoacanthoma (rapidly-growing tumour of the skin derived from the glands surrounding a hair follicle)
- Squamous Cell Carcinoma.
Investigations for BCC?
Dermatoscope examination
* see features making diagnosis likely e.g. (such as arborising vessels, spoke wheel like structures, areas of ulceration).
- Often no other investigations needed unless signs of invasion of other underlyinf structures or mets - need radiological imaging
- Diagnosis confirmed through a biopsy e..g excision biopsy
What factors guide how a BCC is managed?
i.e. tumour subtype
- tumour subtype
- size
- anatomical location
- histological diagnosis
Compare and contrast a Low-risk BCC to a high risk BCC
Low-risk BCCs:
* small
* well-circumscribed lesions
* superficial type lesions
* do not meet any of the high-risk criteria
High-risk BCCs:
* young (<25yrs) or immunocompromised patients
* Recurrent lesions
* lesions on the nose, lips, ears, or around the eyes
* lesions with poorly defined margins
* All non-nodular subtypes of BCC
What are some non surgical management options for BCC?
(often good for superficial BCCs *)
- Cryotherapy (or CO2 ablation)
- Curettage and electrodissection
- Immune response modulator e.g. Topical imiquimod 5% cream* 5 days a week for 6 weeks
- Topical chemotherapy – 5-fluorouracil 5% cream* once daily for 2 weeks
- Photodynamic therapy – light therapy together and topical photosensitising agent*
- Radiotherapy – e.g. older patients
Surgical management for BCCs?
Excision biopsy
* margins 3-5mm (depends on border and location of lesion - 5mm margin if reccurent or high risk histological subtype)
Mohs’ micrographic surgery
* consider if lesion close to vital anatomical structure
* indistinct margins
* recurrent
Once you remove a BCC what are options for closing the site?
- close directly - if enough skin laxity in region
- local, regional free flap or skin grafts
What is Moh’s Micrographic surgery?
When is Moh’s Micrographic surgery useful? (3)
(1) recurring or incompletely removed BCC
(2) areas where it would be cosmetically better to remove as little skin as possible
(3) at sites of previous surgery or radiotherapy.
How to prevent BCC?
- Reduce their exposure to UV light and avoid sunbeds (primary prevention)
- frequent use of SPF50 sunscreen and wearing of protective clothing (secondary prevention).
prognosis for BCC?
BCCs rarely metastasis, prognosis is generally good.
Incomplete excision is more common in periorbital and nasal lesions - incompletely excised BCCs generally have a 30-40% recurrence rate.
Derm BAD book:
prognosis depends on:
- tumour size
- tumour site
- growth pattern, histolological subtype
- failure of previous treatments/recurrance
- immunosuppression
RF for incomplete excision of BCC?
- head lesions
- certain histological subtypes (morphoeic, superficial, infiltrative)
- > 2cm lesions
- > recurrent lesions.
Are pts who have had a BCC at risk of developing further skin cancer?
- 35% risk of developing another non-melanoma skin cancer in 3 years
- 50% risk in 5 years.
What is squamous cell carcinoma SCC?
what does it arise from?
malignant tumour of keratinocytes, arising from the epidermal layer of the skin.
Keratin plug in the middle of the lesion
Most SCC arise from cumulative prolonged exposure to ultraviolet (UV) radiation, primarily UVB.
How common is SCC?
second most common form of skin cancer, after basal cell carcinoma, accounting for 20% of all cutaneous malignancies
Where do SCCs tend to be found? Who are they more common in?
- typically located found on areas exposed to high doses of UV radiation, such as the head & neck, arms, and legs
- more common in men
How does exposure to UV lead to malignancy like SCC?
Exposure to UV radiation causes numerous DNA mutations in multiple somatic genes, such as the p53 tumour suppressor gene.
Are there any premalignant lesions that can lead to SCC?
- Bowen’s disease
- actinic keratoses
- keratin horns
- leukoplakia.
Can SCC metastasise?
uncommon but yes
If SCC does metastasise - how and where?
uncommon but has potential to metastasise via the lymphatic system to regional lymph nodes and any organ:
* lungs
* liver
* brain
* bones
* skin.
RF for SCC?
Cumulative prolonged exposure to UV light
* i.e. excessive sunbed use
Chronic wounds and inflammation
* SCC in chronic ulcers and scars (particularly burns scars) is a Marjolin’s ulcer
Immunosupression
Pre-malignancy conditions
* Bowen’s disease or actinic keratoses
Smoking
* (particularly in lip SCC)
Viruses associated with the development of SCC:
* - HSV, HPV
Clinical features of SCC?
- nodular, indurated, or keratinised
- associated ulceration or bleeding.
- growth over weeks to months
- varibale size mm-cm
- sun-exposed sites e.g. hands, forearms, lower limbs, and “H zone” of the face (pinnae, pre-auricular, medial and lateral acanthi, eyelids, nose and lips).
Differencials for SCC?
- BCC
- melanoma.
- pre-malignant conditions (e.g. Bowen’s disease or Actinic Keratosis
- Keratoacanthoma (rapidly growing keratinising nodules, well-demarcated)
- verrucous carcinoma
- cutaneous horns.
Revision: what is Bowen’s disease?
Investigations for SCC?
- full history and examination
- palpation of regional lymph node basins.
- Dermoscopy white circles or structureless areas, looped blood vessels, and a central keratin plug.
Diagnoiss is from biopsy
* small well-demarcated lesions - excision biopsy with peripheral margins.
* Larger lesions- incisional biopsy for tissue diagnosis.
additional investigations for SCC if suspicious lymph node or mets?
further imaging +/- fine needle aspiration of suspicious nodes should be arranged, as per MDT discussion.
What are the advantages of biopsy techniques below for skin cancer?
- Excisional
- Incisional
- Punch
Histiological grading given to SCCS?
- graded based on their Broder’s grade
- determined by the ratio of differentiated to undifferentiated cells:
Grade I = 3:1
Grade II = 1:1
Grade III = 1:3
Grade IV = no differentiation
SCC can be classified into low risk, high risk, or very high risk lesions. what factors contribute to this?
- size
- thickness
- evidence of perineural invasion or lymphovascular invasion
- degree of differentiation
- presence of clear margins
- location.
How is SCC managed?
- Excision biopsy, with the peripheral margins taken dependent on the risk status of the patient:
low risk ≥ 4mm
high risk ≥ 6mm
very high risk ≥ 10mm
- Wide local excision (with reconstruction), Mohs micrographic surgery, or adjuvant radiotherapy if high risk / multiple lesions
- curettage and cautery for immunocompetent patients who have small (<1cm), clinically low risk SCC
First line - surgery. non-surgical / adjuncts if surgery not feasible.
What are some non-surgical treatments for a pt with SCC?
Primary radiotherapy
* if surgery is not feasible or would result in an unacceptable functional or aesthetic outcome.
Adjuvant radiotherapy
* close or involved margins if further surgery is not possible, clear margins but multiple high risk factors and high chance of recurrence.
Immune Checkpoint Inhibitors
* locally advanced SCC where curative surgery or radiotherapy is not possible/ cases of metastatic SCC.
Chemo
* if not suitable for immune checkpoint inhibitors, poorly tolerated in frailer or co-morbid patients, usually a short lived response.
Prognosis for SCC?
- Low risk SCC - 40% lifetime risk of further skin cancers
- high and very high risk SCC - 80% lifetime risk.
The overall metastatic potential of SCC is 3%, however the 10 year survival for those with metastasis being <10%.
What is a melanoma?
where derived from?
- malignant tumour of melanocytes, the melanin-producing neural crest-derived cells of the body.
- Melanoma commonly arises from melanocytes in the stratum basale of the epidermis
where are melanomas most commonly found?
most commonly on the trunk or legs
Do melanomas metastasise?
YES
* metastasise early, partly due to their vertical growth (as opposed to radially)
* Can spread to nearly every tissue and organ in the body
What are the 4 main histological subtypes of melanoma?
- superficial spreading
- Noodular
- lentigo maligna melanoma
- acral lentiginous
Melanin and UV - how made, how does it protect us from UV?
- Melanin itself is produced in response to UV radiation exposure
- Protects against DNA damage by dissipating >99.9% of absorbed radiation.
RF for melanoma?
UV exposure (sun / sunbeds).
Other:
(Mnemonic PPARENTS)
* Pre malignant lesions
* Previous melanoma
* Age
* Race
* Economic status
* Naevi numbers*, or FAMM syndrome (familial atypical mole and melanoma syndrome),
* Type 1 or tyoe 2 skin (Fitzpatrick skin types),
* Sunbed use
*More than 50 normal naevi confers an increased risk of melanoma
Clinical features of melanoma?
- Early - asymptomatic.
- new mole or changes in an existing mole, such as change in size, shape, colour.
- Advanced - bleeding or ulceration
Examination of a melanoma?
- Asymmetry
- Border irregularity
- Colour uneven
- Diameter >6mm
- Evolving lesion
The patient should be fully examined for features of spread, including regional lymph node involvement.
*Dermoscopy can help triage pigmented lesions, and may show features specific to melanoma
differencials for melanoma?
- melanocytic naevi (darkly pigmented moles)
- pigmented basal cell carcinoma (an uncommon variant of basal cell carcinoma)
- dermatofibroma
- subungual haematoma
- tinea nigra.
any suspected melanoma or suspicious lesion should be referred urgently via the relevant cancer pathway to avoid delay in diagnosis.
Investgations and diagnosis of melanoma?
- exicison biopsy for diagnosis (+ 2mm margin and cutt of subcut fat)
- histological features guide managemnet
- MDT meeting
- the definitive excision markings and further treatment decided abfter histopathology findings.
*Incision or punch biopsies may be acceptable in very large lesions
What are some histological features of a melanoma used the to guide management and prognosis?
NICE recommend a sentinal lymph node biopsy to which pts with melanoma?
- with a Breslow thickness >1 mm, without clinically apparent nodal or metastatic disease.
- SLNB has a high sensitivity and specificity for subclinical regional lymph node involvement, and can give prognostic information.
- If the lymph nodes are clinically or radiologically suspicious, then fine needle aspiration cytology (FNAC) should be performed.
Staging for melanoma is based on TNM staging.
Describe: stage 0-IV
Exhaustive! I think good to kow that III or above it has metastasised
What extra imaging would you perform on a pt with stage III or IV melanoma?
- CT chest-abdomen-pelvis
- MRI brain
- or whole body PET-CT with additional imaging of the brain.
as III and IV mean melanoma has metastasised
After you have biopsied and confirmed melanoma what nect?
- wide local excision
- peripheral margins are guided by Breslow thickness
- note: deep margin should be down to deep fascia
- often done at same time as sentinal node biopsy
- if lymph node mets- lymphadenectomy
Treatment for metastastic melanoma?
Immunotherapies and chemotherapy
Immunotherapy: LOADS! e.g.
Ipilimumab – a monoclonal antibody that inhibits cytotoxic T lymphocyte antigen 4 (CTLA 4), which would normally down regulate T cell activation
Chemo:
dacarbazine: an alkylating agent
Prognosis for melanoma?
strongly correlated with histopathological and individual features. Approximate 5-year survival, based on disease stage are:
Stage 1 – 100%
Stage 2 – 80%
Stage 3 – 70%
Stage 4 – 30%
Prevention of melanoma?
education encouraging reducing exposure to UV light through sun-protection and avoidance of sun beds, and self-checking for new or changing moles.
Patients at high risk for melanoma should receive annual screening.
Skin cancer tutorial:
give margin in mm removed in excision of:
BCC
SCC
melanoma
BCC- 4 mm
SCC- 6mm
Melanom- 2mm. More removed after during wide local excision
skin cancer tutorial : Follow up
1-5 years depending on severity of cancer
e.g. Breslow thickness 1 - FU for 1 year every 3-6 months
What do you call a melanoma that grows on top of a sun spot?
Lentigo melanoma
