Basal Cell Carcinoma Flashcards
What is the most common malignant skin tumour?
Basal cell carcinoma (BCC)
Where do basal cell carcinomas arise from?
Basal keratinocytes in the epidermis
What are the main risk factors for basal cell carcinoma?
(1) UV radiation exposure
(especially childhood sun exposure)
(2) Caucasian skin types I and II
(3) Immunosuppression
(4) Environmental carcinogens
(eg - smoking, ionising radiation)
(5) Trauma
(6) Conditions like xeroderma pigmentosa and oculocutaneous albinism
What is Xeroderma pigmentosum?
Defective nucleotide excision repair
What is Oculocutaneous albinism?
Autosomal recessive absence/defect of tyrosinase resulting in absence of melanin
What is the connection between xeroderma pigmentosum and BCC?
Xeroderma pigmentosum is a condition with defective nucleotide excision repair, increasing the risk of BCC due to impaired DNA repair after UV damage
What are the three main subtypes of basal cell carcinoma?
- Nodular
- Superficial
- Infiltrative (morphotic)
What are the key features of basal cell carcinoma growth and spread?
- Slow-growing and locally destructive
- Rarely metastasises
- May spread via nerves and invade surrounding tissues, leading to significant damage (eg, eye to brain)
ALWAYS CHECK!!!
What is the clinical presentation of basal cell carcinoma?
A non-healing, asymptomatic lesion
What are some distinctive features of BCC?
- Rolled pearly edge
- Central ulceration
- Telangiectasia (visible blood vessels)
What is Telangiectasia?
a blood vessel in the middle
Describe the superficial subtype of basal cell carcinoma
(1) Erythematous, well-demarcated, scaly plaques
(2) Often larger than 20mm
(3) Slightly raised “whipcord” margins
(4) Slow growth over months or years
Describe the nodular subtype of basal cell carcinoma
(1) Slow-growing, shiny, pearly nodule
(2) Superficial telangiectasia
(3) Common on the face
(4) May be ulcerated, referred to as “rodent ulcer” - open sore or ulcer that doesn’t heal
Describe the infiltrative subtype of basal cell carcinoma
(1) Characterised by thickened yellowish plaques
(2) Poorly defined margins
(3) May infiltrate tissues widely
(4) Including nerve involvement
What is a pigmented basal cell carcinoma?
- Brown, blue, or greyish lesion
- Can resemble melanoma
- More common in individuals with darker skin
What are the main investigative methods for diagnosing BCC?
(1) Visual inspection
(2) Removal for histology (all excised specimens must be sent for histopathological examination)
(3) Incisional biopsy for non-surgical treatments before therapy.
What is the management for nodular basal cell carcinoma?
Surgical excision
How are superficial BCCs treated?
Non-surgical treatments including
(1) Cryotherapy
(2) Photodynamic therapy
(3) Topical imiquimod
What is the management for infiltrative basal cell carcinoma?
- Wide excision
- Mohs surgery
= especially for tumours on the nasal creases or recurrent BCCs.
What is Mohs surgery?
A precise surgical technique used to remove skin cancer layer by layer, ensuring complete removal while preserving healthy tissue
What is the role of vismodegib in BCC treatment?
Vismodegib is a targeted treatment for advanced BCCs or for patients who cannot tolerate surgery.
It is a Hedgehog pathway inhibitor that binds to SMO
What type of skin types are most at risk for BCC?
Skin types I and II
(predominantly affecting Caucasians)
A 70-year-old gentleman presents to his GP with a spot on his forehead. Examination reveals a 2cm round lesion with an ulcerated centre.
Given the history and examination findings, what is the most appropriate management?
Excision biopsy (6mm margin)
A 45-year-old man presents with a slow-growing, pink nodule on his forehead which has a central ulceration.
What is the most likely diagnosis?
Basal Cell Carcinoma (BCC)
