Dermatology Flashcards
(122 cards)
Name 3 types of skin malignancies
Basal cell carcinoma
Squamous cell carcinoma
Malignant melanoma
Name and describe 3 layers of the skin
Epidermis (thin outer portion of the skin)
Dermis (thicker inner portion of the skin - comprised of connective tissue, nerves, vessels and sweat glands)
Hypodermis (inner most layer - consists of adipose tissue and sweat glands)
What is the most common form of skin cancer?
Basal cell carcinoma
Define basal cell carcinoma
Describes a non-melanoma form of skin cancer.
BCCs develop slowly in the upper layers of the skin and rarely metastasize.
Give 4 risk factors for basal cell carcinoma
Low geographic latitude (i.e Australia)
Low pigment status (fair skin prone to sunburn)
History of skin cancer
Artificial exposure to UV radiation (especially from a young age)
Which skin layer is affected in by basal cell carcinoma?
Basal cell layer of the epidermis
What genes are usually mutated in basal cell carcinoma?
PTCH and TP53
Name 3 types of Basal Cell Carcinoma. Which is the most common?
Nodular (most common)
Superficial
Morpheaform
Give 5 characteristic features of Nodular Basal Cell Carcinomas
Pearly, Shiny Lesions with;
Rolled Borders
Depressed Centre
Small Arborising telangiectasias
Lesions are sensitive and may bleed with minor trauma
Describe the appearance of a Superficial Basal Cell Carcinoma (2)
Presents as a plaque/patch of well defined, scaly, pink skin.
Mostly occur on the trunk and extremities and in younger patients.
What investigations are required for the definitive diagnosis of a basal cell carcinoma?
Punch Biopsy and Histopathological Examination (minimum)
(other biopsies inc - Excisional, Incisional and Shave)
How are low risk BCCs treated? (2)
Complete surgical removal or Electrodesiccation and Curettage
Give 3 possible complications of BCC
Recurrence
Increased risk of other forms of skin cancer
Disfiguration
What is the leading cause of Squamous Cell Carcinoma?
UV exposure (Specifically UVB rays)
Chronic UVB exposure damages the DNA of squamous Keratinocytes, leading to tumour formation.
What gene is commonly mutated in Squamous Cell Carcinoma?
P53 Tumour Suppressor Gene
Give 4 risk factors for Squamous Cell Carcinoma
UV radiation (specifically UVB)
Immunosuppression
Increasing age
Fitzpatrick Skin types I and II (fairer skin)
Give 4 typical physical features of Squamous Cell Carcinoma
Firm to palpate (may be nodular/plaque-like)
May ulcerate and bleed
May be tender or painful
May have crusty keratotic top with a nodular base
Where do squamous cell carcinoma’s tend to appear?
In sun-exposed areas (e.g lips, back of hands, upper part of face or scalp)
Cancerous mutations in which cells causes the formation of squamous cell carcinoma?
In squamous keratinocytes in the epidermis (outermost layer of the skin)
Give 3 differentials in the context of suspected Squamous Cell Carcinoma
Actinic keratosis
Basal Cell Carcinoma
Seborrhoeic Keratosis
Describe Actinic Keratosis
Describes the formation of precancerous scaly lesions on the skin.
Have a 10% risk of developing into SCC, therefore must be monitored and treated accordingly.
How should SSC’s be investigated? What indications are used for each type of biopsy?
Biopsy and histological examination
Excisional or Shave biopsy - Removes whole lesion. Is used if lesion is small, accessible and not in a cosmetically sensitive area.
Incisional/punch biopsy - Used on large lesions as only samples a small (usually 4mm) part of the lesion.
If metastasis of an SCC is suspected, what other investigations is it important to perform? (2)
Ultrasound of Lymph Nodes
CT and MRI for staging or if metastasis is suspected.
Give 4 indicators of a poor prognosis for squamous cell carcinoma
Poorly differentiated tumours (histologically)
> 20mm in diameter
> 4mm deep
Patient is immunosuppressed