Basal Cell Carcinoma Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What is BCC?

A

BCC aka rodent ulcer starts in basal cells lining the bottom of the epidermis, which produces new cells constantly as older cells shed off.

=> very slow growing,

=> locally invasive epidermal skin tumour,

=> rarely metastasizes

=> occurs mainly on areas of chronic sun exposure i.e. the face, head and neck

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the types of BCC?

A

There are four types:
• Nodulocystic – most common on face and neck

  • Superficial – most common on trunk; may mimic psoriasis, discoid eczema and Bowen’s
  • Pigmented - heavily pigmented BCCs can resemble melanoma
  • Morphoeic – may resemble a scar; difficult to diagnose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How common is BCC?

A

BCC is the most common skin cancer => ~ 80% of all skin cancers

80% occur on the head and neck and rest on trunk and legs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Who does BCC affect?

A

Predominantly fair skinned types

More common at altitude and near the equator

Mostly affects over 50s

Males more than females

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What causes BCC?

A

BCC is caused by sun exposure and DNA damage due to UV light.

DNA repair is able to remove most UV-induced damage but cumulative damage leads to mutations.

=> common mutations in the PTCH1, PTCH2, SMO and SUFU genes predispose to BCC.

Gorlin syndrome/Nevoid basal cell carcinoma syndrome = inherited condition
=> predisposes to recurring non-melanoma skin cancers.
=> born with one mutated allele of the PTCH1 gene leads to an autosomal dominant syndrome of cancer predisposition.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the risk factors for BCC?

A

UV light - chronic sun exposure/tanning beds (greater risk in high altitude/near the equator = increased UV radiation ; severe sunburns)

Genetic factors (PTCH1 gene mutation)
Immunosuppression

Fair skin - People who freckle or burn easily or who have very light skin, red or blond hair, or light-colored eyes.

Previous BCC/family hx

Age - BCC takes decades to develop

Radiation therapy

Chronic arsenic exposure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the signs & symptoms of BCC?

A
  1. Painless lesion
  2. Slow growing
  3. Does not heal with medication
  4. Can occasionally bleed
1. Nodulocystic:
=> Dome-shaped
=> Pearly white nodule
=> Papule
=> Telangiectasia (small blood vessels form threat-like patterns)
=> Smooth surface, rolled over edges
=> Old tumours may present as central ulcerated nodules (rodent ulcer)
=> Most common type of facial BCC
2. Superficial:
=> Scaly erythematous plaques
=> Well-defined raised pearly edges
=> Most common in younger adults
=> Most common type on upper trunk and shoulders
=> Microerosions
  1. Pigmented:
    => All BCC types can contain flecks of pigment
    => Pearly appearance
    => Heavily pigmented => BCCs can resemble melanoma
4. Morphoeic:
=> Ill-defined borders
=> Waxy, scar-like indurated plaque
=> Wide and deep sub-clinical extension
=> May infiltrate cutaneous nerve 
=> Usually found in mid-facial sites
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the differentials for BCC?

A
1. Nodular:
=> Intradermal naevus
=> Sebaceous hyperplasia
=> Fibrous papule
=> Molluscum contagiosum
=> Keratoacanthoma
2. Superficial:
=> Psoriasis – multiple lesions; bilateral; almost symmetrical; fluctuating in nature
=> Discoid eczema multiple lesions; diffuse; fluctuating in nature
=> Bowen’s disease 
=> Actinic keratosis 
=> SCC 
=> Lichen simplex
=> Seborrhoeic keratosis
  1. Pigmented:
    => Melanoma
  2. Morphoeic:
    => Scar tissue
    => Localised scleroderma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the investigations for BCC?

A

Clinical diagnosis

Diagnosis and histological subtype confirmed pathologically by biopsy

Clinical examination for lymphadenopathy – no other staging required; CT or MRI indicated in cases where bony involvement suspected or tumour may have invaded major nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the treatment for BCC?

A

Surgical:

1. Excision
•	Gold standard
•	4mm margin required
•	Primary closure, flap or graft
•       Appropriate for nodular, infiltrative and morphoeic BCCs
  1. Curettage and cautery (Superficial skin surgery)
    • Curette used to scrap off soft material
    • Base of tumour destroyed by cauterisation
    • Used for small, primary BCCs
    • Histology may be difficult to interpret
  2. Mohs’ micrographic surgery
    • Excision carried out in stages with each stage checked histologically
    • Useful for morphoeic cancers with ill-defined margins, infiltrative, locally recurrent BCCs or sites where it is important to preserve tissue e.g. adjacent to eye, lips and nose
    • Very high cure rates
  3. Cryotherapy/cryosurgery
    • Small, low-risk lesions on trunks and limbs
    • Biopsy would need to be taken first

Non-surgical:

1. Topical treatment
Imiquimod 5% cream
•	Immune response modifying agent
•	Small, superficial BCCs
Fluorouracil 5% cream - cytotoxic agent
•	Useful for multiple superficial BCCs on trunk and limbs
  1. Photodynamic therapy (PDT)
    • Light therapy in combination with topical photosensitising agent to destroy cancer cells
    • Best for superficial BCC, low risks ; avoided if tumour at high risk of recurrance
    • Requires 3-4 hour of treatment
  2. Radiotherapy
    • Useful for people unsuitable for surgery or margins of excision appear to be incomplete
    • Surgery required for reoccurrence
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the prognosis for BCC?

A

Excellent prognosis

Metastasis and death are extremely rare

Recurrence rates very low with complete excision, but can be up to 50%
Prognosis for recurrent BCCs is lower

Risk of developing more BCCs increases with previous BCC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the complications of BCC?

A
  1. Recurrent BCC

Characteristics of recurrent BCC often include:

=> Incomplete excision or narrow margins at primary excision

=> Morphoeic, micronodular, and infiltrative subtypes

=> Location on head and neck

  1. Advanced BCC

=> Advanced BCCs are large, often neglected tumours.

=> They may be several centimetres in diameter

=> They may be deeply infiltrating into tissues below the skin

=> They are difficult or impossible to treat surgically

  1. Metastatic BCC

=> Very rare

=> Primary tumour is often large, neglected or recurrent, located on head and neck, with aggressive subtype

=> May have had multiple prior treatments

=> May arise in site exposed to ionising radiation

=> Can be fatal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly