1b Skin Cancer Flashcards
What are the 5 layers of skin?
Come Let’s get sun burnt!
What are 5 points of self detection for skin lesions that may turn cancerous?
ABCDE
What is a malignant melanoma?
-
Malignant tumour arising from melanocytes
- Leads to > 75% of skin cancer deaths
Can arise on mucosal surfaces (e.g. oral, conjunctival, vaginal) and within uveal tract of eye
Outline the epidemiology of malignant melanomas.
- Rising incidence rates observed worldwide
- Develops predominantly in Caucasian populations
- Incidence low amongst darkly pigmented populations
- 10-19/100,000 per year in Europe, 60/100,000 per year in Australia / NZ (Sunny locations)
What are the risk factors of malignant melanomas (Genetic 3 / Environmental 3 / Phenotypic 2)?
Genetic factors:
* Family history (CNKN2A mutations), MC1R variants
* Lightly pigmented skin, red hair
* DNA repair defects (e.g. xeroderma pigmentosum)
Environmental factors:
* Intense intermittent sun exposure, chronic sun exposure, residence in equatorial latitudes
* Sunbeds
* Immunosuppression
Phenotypic:
* Patient who has more than 100 melanocytic nevi on the whole body
* Patient who has atypical melanocytic nevi
What are the main different subtypes of malignant melanoma (5)?
- Superficial spreading (Horizontal growth then Vertical growth)
- Nodular (Only vertical growth)
- Lentigo maligna
- Acral lentiginous
- Unclassifiable
A patient present with the following symptoms:
What is the most likely diagnosis?
- Superficially spreading malignant melanoma
Epidemiology:
* 60-70% of all melanomas
* Most common type in fair-skinned individuals
* Most frequently seen on trunk of men and legs of women
Pathogenesis:
* Can arise de novo or in pre-existing nevus
* In up to 2/3 of tumours, regression (visible as grey, hypo-or depigmentation), due to host immune system reacting to tumour
Pathophysiology:
* After a slow horizontal (radial) growth phase, limited to epidermis, a more rapid vertically oriented growth phase: development of nodule
Differential diagnosis:
* Dermatofibroma
A patient present with the following symptoms:
What is the most likely diagnosis?
- Nodular malignant melanoma
Epidemiology:
* 2nd most common type of melanoma in fair skinned individuals
* 15-30% of all melanomas
* Most commonly trunk, head and neck, M>F
Pathogenesis:
* Usually dark nodule -but can be pink or red, may be ulcerated, bleeding
* Develops rapidly
Pathophysiology:
* De novo vertical growth phase without the horizontal growth phase. Present more advanced stage, with poorer prognosis.
Differential diagnosis:
* Basal cell carcinoma
A patient present with the following symptoms:
What is the most likely diagnosis?
- Lentigo maligna (malignant melanoma)
Epidemiology:
* 5% progress to invasive melanoma
* > 60 yo chronically sun damaged skin
Pathophysiology:
* Slow growing macule
* It is an in-situ melanoma
Differential diagnosis:
* Seborrhoeic keratosis
A patient present with the following symptoms:
What is the most likely diagnosis?
- Acral lentiginous (malignant melanoma)
Epidemiology:
* Uncommon: ~5% of all melanomas
* Most frequently 70yo
* Incidence similar across all age groups
What investigations are suggested in suspected malignant melanomas (2)?
- Examination with a dermatoscope
- Excision biopsy for histological assessment
- Measure Breslow thickness: prognosis worse if >1mm
What is the management of malignant melanomas (Surgery 2 / Imaging 1 / Immunotherapy 2)?
Surgery:
* Wide local excision
* Margin depends on Breslow thickness
* Sentinel lymph node biopsy - lymph node dissection
Imaging:
* TNM staging
Immunotherapy:
* CTLA-4 inhibition (Ipilimumab)
* PD-L1 (Programmed cell death ligand) inhibitors
* (Nivolumab)
What are the 3 stages of keratinocyte dysplasia?
Actinic keratoses
* Dysplastic keratinocytes
Bowen’s disease
* Squamous cell carcinoma in situ
Squamous cell carcinoma
* Invasive cancer
* Potential for metastasis/ death
Predominantly pale skin types
Solar induced UV damage
A patient present with the following symptoms:
What is the most likely diagnosis?
Actinic keratoses
* Dysplastic keratinocytes
A patient present with the following symptoms:
What is the most likely diagnosis?
Bowen’s disease
* Squamous cell carcinoma in situ
What is the management of actinic keratosis and bowen’s disease (6)?
- 5-fluorouracil cream
- Cryotherapy
- Imiquimod cream
- Photodynamic therapy
- Curettage and cautery
- Excision
A patient present with the following symptoms:
What is the most likely diagnosis?
- Squamous Cell Carcinoma (SCC)
Pathophysiology:
* Can have different appearances
* Erythematous to skin coloured
* Papule
* Plaque-like
* Exophytic
* Hyperkeratotic
* Ulceration
* Arises within background of sun-damaged skin
* Rapidly growing
Differential diagnosis:
* Basal cell carcinoma
* Viral wart
* Merkel cell carcinoma
What investigations are recommended for suspected squamous cell carcinoma (SCC) (2)?
Often clinical diagnosis sufficient
- Diagnostic biopsy may be taken if diagnostic uncertainty
- Ultrasound of regional lymph nodes ± FNA if concerns regarding regional lymph node metastasis
What is the management of squamous cell carcinoma (SCC) (5)?
- Examination of rest of skin and regional lymph nodes
- Excision
-
Radiotherapy
- Unresectable
- High risk features e.g. perineural invasion
- Cemiplimab for metastatic SCC
- Secondary prevention
- Skin monitoring advice
- Sun protection advice
A patient present with the following symptoms:
What is the most likely diagnosis?
-
Keratoacanthoma
- Pseudo-malignancy VS Variant of SCC (still unclear)
- Rapidly enlarging papule that evolves into a sharply circumscribed, crateriform nodule with keratotic core
- Resolves slowly over months to leave atrophic scar
- Most occur on head or neck / sun exposed areas
- Difficult to distinguish clinically and histologically from squamous cell carcinoma, so often excision
A patient present with the following symptoms:
What is the most likely diagnosis?
- Basal Cell Carcinoma (BCC)
Main subtypes: Nodular- Superficial
* Nodular:
* Most common subtype
* Approximately 50% of all BCCs
* Typically: shiny, pearly papule or nodule
* Superficial:
* Well-circumscribed, erythematous, macule/plaque
Differential diagnosis:
* Squamous cell carcinoma
* Adnexal (Sebaceous) carcinoma
* Merkel cell carcinoma
What investigations are recommended for suspected basal cell carcinoma (BCC) (1)?
Often clinical diagnosis sufficient
- Diagnostic biopsy may be taken if diagnostic uncertainty
What is the management of basal cell carcinoma (BCC) (1)?
- Standard surgical excision
A patient present with the following symptoms:
What is the most likely diagnosis?
- Merkel Cell Carcinoma
What is melanoma
Malignant tumour arising from melanocytes
most common sc death (over 75%)
Where can melanoma arise besides regular skin
Can arise on mucosal surfaces (e.g. oral, conjunctival, vaginal) and within uveal tract of eye
genetic risk factors for skin cancer
Family history (CNKN2A mutations), MC1R variants
Lightly pigmented skin
Red hair
DNA repair defects (e.g. xeroderma pigmentosum)
environmental risk factors for melanoma
Intense intermittent sun exposure
Chronic sun exposure
Residence in equatorial latitudes
Sunbeds
Immunosuppression