17 - Benign and Malignant Skin Tumours Flashcards
How can skin cancers for classified?
- Melanotic (malignant melanoma)
- Non-melanotic (BCC and SCC)
What is an Actinic Keratosis and what does it look like?
Premalignant scaly spot found on sun-damaged skin e.g face, hands, back, arms
Can regress or can progress to SSC
Often looks crumbly with yellow-white crust (keratotic) if solitary or erythematous if multiple
Features
• small, crusty or scaly, lesions
• may be pink, red, brown or the same colour as the skin
• typically on sun-exposed areas e.g. temples of head
• multiple lesions may be present
What are some differential diagnoses for Acitinic Keratoses?
- BCC
- Bowen’s
- Psoriasis
- Seborrhoeic keratosis
IF IN DOUBT BIOPSY!
What is the epidemiology of Actinic Keratoses?
- Fair skin with history of sunburn
- History of long hours spent outdoors for work or recreation (e.g lived abroad)
- Immunocompromised
What is the simple way to tell the difference between an acitinic keratoses and seborrheic keratoses?
AK usually are flat or slightly raised that cannot be moved but SK can move and look like they are stuck on like a sticker
Also SK can be tan coloured
AK is a precursor for SSC. What advice can you give to patients if they have AKs to prevent the progression?
- Avoid sun/wear sunscreen
- Wear hats and clothes that cover the skin
- Advise patient to monitor skin and educate them that it can predispose to skin cancer.
How are actinic keratoses treated?
Solitary/Keratotic/Thick Crust Lesions:
- Cryotherapy
- Shaving/Curettage
- Surgical excision, pathology and stitches
Field/Flat Red Lesions:
- 5-Fluorouracil cream
- Imiquimod cream is an immune response modifier
- Diclofenac cream
- Photodynamic therapy
How does photodynamic therapy work?
Light sensitive medicine is applied then light is applied to the area and this produces free radicals and causes cell death
What is Bowen’s Disease and what does it look like?
SCC in-situ
Pink/Red scaly patches/plaques - 10-15 mm in size, slow growing, often on sun exposed areas
Flat edges NOT rolled like BCC
It is more common in elderly patients. There is around a 5-10% chance of developing invasive skin cancer if left untreated.
Bowen’s disease is a type of precancerous dermatosis that is a precursor to squamous cell carcinoma.
What are some risk factors for developing Bowen’s disease?
- Sun exposure
- Immunosuppressants
- Immunosuppression e.g lymphoma
- Radiation
- Arsenic
- HPV
How is Bowen’s disease diagnosed?
- Dermascopy: will show red irregular scaly plaque with crops of rounded and coiled blood vessels
- Biopsy: will show full thickness dysplasia
How is Bowen’s disease treated?
It can turn to SCC but unlikely. If it does go to SCC then likely to metastasise
- Observe
- Cryotherapy with liquid nitrogen
- Curretage
- 5Fluorouracil
- Imiquimod (off-licence)
- Photodynamic therapy
HOW CAN YOU TELL THE DIFFERENCE BETWEEN AK, BOWEN’S AND SCC?
will come back to
What is the prevalence of different skin cancers?
Most common to least:
- BCC
- SCC
- MM
How does an SCC (cancer of keratinocytes) present?
- Firm irregularly defined nodule that may persistently ulcerate and crust
- Usually on sun-exposed areas
- Often grow quickly and tender to touch
- Invasive and has the potential to metastasise
What are the risk factors for developing an SCC?
- Excessive UV exposure e.g occupation, lived abroad
- Pre-malignant skin e.g AK
- Chronic inflammation e.g leg ulcer, cutaneous lupus, HPV
- Immunosuppresion
- FHx
- Skin type 1
- Xeroderma pigmentosa
Which types of SCC are more likely to metastasise?
- Lip
- Ear
- Non sun-exposed site
- >2cm diameter or >2mm thick
- Host immunosuppression
How is SCC investigated and diagnosed?
- Dermascopy
- Biopsy or excision then biopsy
- Consider lymph node biopsy and MRI if think it has metastasised
How is SCC treated?
- Complete surgical excision with margins of normal tissue around the outside. May need flap to close
- Moh’s micrographic surgery for ill-defined, large, or recurrent tumours
- Radiotherapy if large and non resectable tumour
Surgical excision with 4mm margins if lesion <20mm in diameter. If tumour >20mm then margins should be 6mm. Mohs micrographic surgery may be used in high-risk patients and in cosmetically important sites.
What is the pathophysiology of SCC?
- UV light causes mutation in p53 tumour suppressor gene
- Ageing, smoking, immunosuppressants (e.g Azathioprine), HPV also induce mutations in tumour suppressor genes
- Allows keratinocytes to mutate and reproduce without being killed
What is the prognosis of BCC? (Rodent Ulcer)
- Most common skin cancer
- Very slow growing
- Rarely metastasises
- Often recurrent
- Increased risk of developing other skin cancers
What are some risk factors for BCC?
- UV exposure
- History of severe/frequent sunburn in childhood
- Skin type 1
- Increasing age
- Male
- Immunosuppressed
- Previous history of skin cancer
- FHx (Genetic Predisposition)
What are the different presentations of BCC?
Nodular (most common)
- Small skin coloured or pink nodule with surface telangiectasia and pearly rolled edge.
- May have necrotic or ulcerated centre (rodent ulcer)
- TURP
Superficial
- Scaly irregular plaque with microerosions on younger patients
- Morphoeic
- Basosquamous
How do you describe a nodular BCC?
Small skin coloured papule/nodule with surface telengactasia and a pearly rolled edge
Can have a ulcerated or necrotic centre (rodent ulcer)
How is a BCC treated?
- Surgical excision with 3-5mm borders of normal tissue and histopathology (non-urgent referral)
- Mohs Micrographic surgery if high risk, recurrent tumours
- Shave, Curettage, Cryotherapy, Topical PDA, Topical Imiquimod if small and well-defined low risk tumour
What defines a BCC as being high risk?
What is malignant melanoma and what are the risk factors for developing this?
Invasive malignant tumour of melanocytes with the potential to metastasise
- UV exposure
- Sunburn
- Skin type 1
- >50 melanocytic or atypical moles
- Family history
- Previous melanoma
- Old age
What are some pre-cursor lesions for malignant melanoma?
- Benign melanocytic naevus (normal mole)
- Atypical or dysplastic naevus (funny-looking mole)
- Atypical lentiginous junctional naevus (flat naevus in heavily sun damaged skin) or atypical solar lentigo
- Large congenital melanocytic naevus (brown birthmark)
75% OF MELANOMAS ARISE FROM NORMAL SKIN
What are the stages of growth for melanoma?
- Benign naevus
- Dysplastic naevus
- Radial growth phase
- Vertical growth phase
- Metastases
How do melanomas tend to present?
ABCD Superficial, EFG Nodular
A - Asymmetrical shape
B - Border irregularity
C - Colour irregularity
D - Diameter > 6 mm
E - Evolution (change in size or shape)
Symptoms - Itchy, Bleeding, Crusting
E - Elevated
F - Firm to touch
G - Growing
Usually on legs in women and trunk in men
What is the 7 point checklist?
2 for each major, 1 for each minor
Anything 3 or more needs urgent 2ww referral
What are the different types of melanoma (most to least common) and how do they present differently?
Superficial Spreading ABCDE:
- Most common. Grows on lower limbs. UV exposure
- Radial growth phase then vertical
Nodular EFG:
- Second most common
- Aggressive
- Grow vertically first so more advanced at presentation
Lentigo Maligna:
- Common on the face of elderly
- Chronic sun exposure
- Long period of intraepithelial growth so slow
Acral Lentigous
- Usually on palms, soles of feet, nails
- Hutchinson’s sign (2ww)
- Not linked to UV exposure
Desmoplastic
- Often amelanocytic!!!
How is a suspected melanoma diagnosed and managed generally?
Surgical excision under local anaesthetic and send for histopathology is the investigation and treatment. Take 2mm margin of ‘normal’ skin and cuff of subcutaneous fat around the mole
Wide local excision may then be needed after results if malignant
NEVER SAMPLE, NEED TO EXCISE WHOLE THING!
How does the histology of a melanoma determine the prognosis?
- Breslow thickness (strongest prognostic indicator): measures from S.Granulosum to deepest part of infiltration
- Ulceration: more aggressive so worst prognosis
- Mitotic Index
- Stage of Melanoma (AJCC)
- FNA and Cytology of lymph nodes
How is malignant melanoma staged?
American Joint Committee on Cancer (AJCC) system
Based on Breslow thickness of primary tumour, lymph node involvement and evidence of metastases
Stage 1 to 4
How is a melanoma treated after it has been surgically excised and proven histologically to be malignant?
Non-metastatic:
- WLE: removal of the biopsy scar with a surrounding margin of ‘healthy’ skin, with fat, down to muscular fascia. Margin depends on Breslow thickness
- Sentinel node biopsy and clearance if positive
- ?Radiotherapy
Metastatic:
- Chemotherapy
- Immunotherapy
What is a dermatofibroma?
Dermatofibromas (also known as histiocytomas) are common benign fibrous skin lesions. They are caused by the abnormal growth of dermal dendritic histiocyte cells, often following a precipitating injury. Common areas include the arms and legs.
Features
* solitary firm papule or nodule, typically on a limb
* typically around 5-10mm in size
* overlying skin dimples on pinching the lesion
What is a pyogenic granuloma?
Pyogenic granuloma is a relatively common benign skin lesion. The name is confusing as they are neither true granulomas nor pyogenic in nature. There are multiple alternative names but perhaps ‘eruptive haemangioma’ is the most useful.
The cause of pyogenic granuloma is not known but a number of factors are linked:
* trauma
* pregnancy
* more common in women and young adults
Features
* most common sites are head/neck, upper trunk and hands. Lesions in the oral mucosa are common in pregnancy
* initially small red/brown spot
* rapidly progress within days to weeks forming raised, red/brown lesions which are often spherical in shape
* the lesions may bleed profusely or ulcerate
Management
* lesions associated with pregnancy often resolve spontaneously post-partum
* other lesions usually persist. Removal methods include curettage and cauterisation, cryotherapy, excision
What is a kertoacanthoma?
Keratoacanthoma is a benign epithelial tumour. They are more common with advancing age and rare in young people.
Features - said to look like a volcano or crater
initially a smooth dome-shaped papule
rapidly grows to become a crater centrally-filled with keratin
Spontaneous regression of keratoacanthoma within 3 months is common, often resulting in a scar. Such lesions should however be urgently excised as it is difficult clinically to exclude squamous cell carcinoma. Removal also may prevent scarring.
