Basal cell carcinoma - an overview

Patient Information Leaflet
Link: Basal cell carcinoma

https://pcds.org.uk/patient-info-leaflets/basal-cell-carcinoma

Basal cell carcinoma (BCC) is the commonest from of skin cancer accounting for approximately 70% of all skin cancers. BCC are composed of cells similar to those in the basal area of the epidermis and its appendages. The estimated lifetime risk for BCC in the white population is 33-39% for men and 23-28% for women. Reliable statistics on the incidence of non-melanoma skin cancer (NMSC) are difficult to obtain, but it is estimated that around 100,000 people are diagnosed with NMSC each year in the UK.

While BCC very rarely metastasize, they can cause significant morbidity by local tissue invasion and destruction, particularly on the head and neck. 

This chapter provides an overview on BCC and is set out as below. More detailed information can be found in the related chapters.  

• BCC tend to be slow growing, often increasing in size by 2-4 mm a year; occasionally faster
• Most lesions are reported by the patient as never fully healing and periodically bleed or produce a scab

Distribution

• Although the majority occur on the head and neck, any part of the body can be affected - BCC can be multiple so a thorough skin examination is needed
• The incidence of superficial BCC, especially on the trunk is increasing significantly, especially in younger patients
• BCC are uncommon on the forearms and hands, and are very rare on non-hair bearing parts of the body

Morphology - general

• Lesions often produce a bloody crust as opposed to the scale found in keratinising tumours such as actinic keratoses and SCC
• May contain pigment

The exact appearance (naked-eye and dermoscopic) depends on the type - refer to the related chapters (top right of page).  

• Lesions reported histologically as having a squamous component (basosquamous) should be managed as a squamous cell carcinoma

General

• Provide a patient information leaflet
• Direct patients to the section of this website on self-examination

Surgical treatment 

• Is first-line for the majority of BCC, except for superficial BCC (refer to the related chapter). Just occasionally a patient may not be fit for surgery, but if on a high-risk site the case will still need to be discussed with a local consultant who is part of the skin cancer MDT, as other options such as skin radiotherapy or medical treatment may be recommended
   
• In standard skin surgery lesions should be excised with a 4 mm margin of normal surrounding skin. Some high-risk lesions are managed in Secondary Care with Mohs surgery (Mohs micrographic surgery), a very time consuming, yet accurate and tissue sparing technique (not available in all localities)

Who can manage BCC (England and Wales)?

• Diagnostic uncertainty - the patient should be referred to either a nationally accredited GPwER in Dermatology or a Secondary Care department skilled in dermoscopy
   
• Diagnostic certainty in low-risk BCC beneath the clavicle - if the lesion is not on the exclusion list (see below) the patient can be managed by nationally accredited Group 2 and 3 GPwERs, or, GPs meeting the requirements to perform skin surgery within the framework of the Direct Enhanced Services and Local Enhanced Services under General Medical Services or Personal Medical Services
   
• Diagnostic certainty in low-risk head and neck lesions - if the lesion is not in the exclusion list (see below) the patient can be managed by some nationally accredited Group 2 and 3 GPwERs (check locally), but not GPs
   
• High-risk BCC should be managed in Secondary Care, and only by individuals with appropriate surgical skills (plastic surgeons, some dermatologists, and in some regions the departments of Oral and Maxillofacial Surgery and Oculoplastics)

High-risk factors warranting referral to Secondary Care (exclusion list for Primary Care) 

The patient

• Aged 24 years or under
• Immunosuppressed (especially renal and other transplants) or have Gorlin syndrome

All head and neck lesions that are any of:

• Poorly-defined
• > 1 cm diameter
• On/bordering the nose and lips (including nasofacial sulci and nasolabial folds), ears, or around the eyes (periorbital)
• Over important underlying anatomical structures (for example, major vessels or nerves)
• Morphoeic, infiltrative or basosquamous in type

All lesions beneath the clavicle that are any of:

• At a site where primary closure is unlikely to be achievable
• Morphoeic, infiltrative or basosquamous in type

GPs are also discouraged to excise BCC at sites of high cosmetic importance.

For more information on the management of BCC refer to the British Association of Dermatologists Guidelines.