Skin cancers

Scottish referral guidelines for suspected cancer
Centre for Sustainable Delivery

Urgent suspicion of cancer (USC) referral

Refer a person with any of the following according to the local skin cancer pathway as a USC:

  • Skin or nail lesion suspicious for melanoma
  • Skin or nail lesion suspicious for squamous cell carcinoma (SCC)
  • Skin lesion suspicious for a basal cell carcinoma (BCC) invading a potentially dangerous area e.g. peri-ocular, auditory meatus, nerve, or major blood vessel
  • Skin lesion whose features raise concern for malignancy (see – other skin lesions that are concerning for malignancy)
  • Unexplained or concerning skin lesion in an immunocompromised person
  • A biopsy proven melanoma, SCC, or high-risk BCC (infiltrative, micronodular, or basosquamous)

 

Assessment for suspected skin cancers

The lesion should be examined and, if available, assessed using a dermatoscope. The dermatoscope is a useful tool for distinguishing benign pigmented lesions (e.g. seborrheic keratosis) from melanoma, potentially reducing unnecessary referrals. The Right Decision Service contains useful CfSD resources to aid in the assessment of skin lesions.

If the lesion is suspicious of cancer, a full medical history should be documented and the entire skin surface should be examined. History should include drugs, conditions that cause immuno-compromise, prior personal and family history of skin cancer.

 

Melanoma:

Suspect this if there is:

  • A mole* with any of the following features (ABCDE criteria):
    • Asymmetry
    • Border (irregular, scalloped or poorly defined)
    • Colour (irregularity or darkening)
    • Diameter more than 6 millimetres (they can be smaller)
    • Evolution in shape, size, or colour (especially if quickly)
  • A mole which stands out from those around it (the ‘ugly duckling’ sign)
  • A new mole developing in a person aged 40 or over

*See good practice section below for the assessment of pigmented lesions

 

Subungual melanoma:

Suspect this if there is:

  • Nail pigmentation which evolves but remains in contact with and/or involves the nail fold (fold of skin that borders the bottom and sides of the nail)

 

Squamous cell carcinoma (SCC):

Suspect this if a person with a skin lesion has one or more of the following features:

  • Hyperkeratotic (scaly) nodule or indurated (thickened) lesion
  • Ulcerated nodule that may bleed easily
  • Lesion is painful or tender on palpation
  • Lesion grows over weeks to a few months
  • There is background of actinic keratosis

 

Squamous cell carcinoma (SCC) of the nail apparatus:

Suspect this if there is:

  • A lesion growing underneath the nail that may be associated with local tissue destruction
  • A change such as a nodule growing in an established periungual wart

 

Basal cell carcinoma (BCC):

Suspect this if a skin lesion has one or more of the following characteristics:

  • Ulcer with a raised rolled edge, a nodule on the skin (waxy or pearly), a reddish plaque, scar-like with tethering or contraction
  • Prominent fine blood vessels within the lesion
  • History of spontaneous bleeding
  • May contain pigmented areas
  • Rarely painful

 

Other skin lesions that are concerning for malignancy:

The following skin changes should raise concern for a malignant lesion (including Merkel's tumour, sarcoma, or amelanotic melanoma):

  • Nodule grows quickly (over weeks)
  • A new change (growth, pigmentation, or pain) in a long-standing ulcer, scar, traumatic or inflamed area of skin
  • Non-healing and/or destructive atypical ulcer
  • Progressive unexplained scar-like area
  • An unexplained skin lesion with loco-regional lymphadenopathy

Good practice points

Pigmented lesions:

Not all pigmented skin lesions are melanomas. Seborrheic keratoses are common, benign, pigmented lesions that can change in colour, size, and shape. They have a classical ‘stuck on’ appearance and can easily be distinguished with a dermatoscope. It is important to recognise these benign lesions as application of the ABCDE criteria may result in over-referral for suspected melanomas. Lesions which are suspicious for melanoma should not be removed in primary care.

 

Subungual melanoma:

This is rare compared with other causes of nail discolouration and change including fungal infection and haematoma. A subungual haematoma will grow out distally resulting in normal nail proximally between the nail pigmentation and the nail fold.

 

Other considerations:

  • Any skin lesion removed should be sent for pathological examination
  • Referrals should be accompanied by an accurate description of the lesion – including size (with measurements), pain, and tenderness
  • A photograph of the lesion should be sent with the referral to secondary care wherever possible. This allows for accurate and timely triage increasing the efficiency of care for patients with skin cancer. Please follow local pathways.
  • Please visit the Right Decision Service for CfSD primary care management of skin lesions not referred as a USC
  • GPs with a special interest in dermatology can often safely manage SCCs and BCCs in primary care, including excision
  • Dentists play a key role in the identification of cancers on the skin, in particular of the face and neck. There should be systems in place for USC referral pathways for dentists

 

Background

The main types of skin cancer are basal cell carcinoma (BCC), cutaneous squamous cell carcinoma (SCC), and melanoma. There are also several much rarer skin cancer types.

BCC is the most common type of skin cancer (around 75% of all skin cancers diagnosed)65. It develops from basal cells, found in the deepest part of the outer layer of the skin (the epidermis). It is rare for basal cell skin cancer to metastasise.

SCC begin in cells called keratinocytes which are found in the epidermis. SCC is faster growing than basal cell cancers. It is unlikely to metastasise (research suggests metastases found in 1.2-5% of cases)66. Around 23% of skin cancers are SCCs65.

Melanoma accounts for around 1% of diagnosed skin cancers65. Melanoma skin cancer typically starts in skin cells called melanocytes1.

In England there are more USC referrals for skin cancer than for any other site, with referral rates increasing more than threefold between 2009/2010 and 2022/2023, while conversion rates have fallen67,68. PHS plans to publish data on USC referrals once data quality issues have been resolved.

Risk factors for all skin cancer types include:

  • Excessive sunlight exposure and sun bed use and is highest in people with fair skin colour and a susceptibility to sunburn

Risk factors for melanoma include:

  • Large number of benign melanocytic naevi (greater than 100 naevi has been shown to increase the relative risk of developing melanoma approximately sevenfold compared with 15 or less naevi)69
  • A family history of melanoma

Risk factors for SCC include:

  • Multiple small actinic keratoses
  • High levels of previous UV-A photochemotherapy
  • Being immunocompromised

Skin cancers are very infrequent in those aged under 15 years of age.

Skin cancer can affect people of all skin colours, including those with brown and black skin. Skin cancer on darker skin often occurs on areas that get little sun exposure, like the palms of hands, soles of feet, and under/around the nails. People of colour have a higher risk of a late diagnosis and poorer prognosis as skin cancer may be less noticeable or less expected in their skin.