QuestionSBA
QuestionChoice
This case describes an actinitc keratosis undergoing malignant transformation to a squamous cell cancer. Signs of malignant transformation include enlarging, becoming hyperkeratotic, nodular and showing a poor response to treatment.
10015856
a
2 week referral to dermatology
QuestionChoice
This is not appropriate given the concerning presentation, lack of treatment response and patient's distress.
10015857
b
Discharge with reassurance
QuestionChoice
This may be indicated in the treatment of the likely SCC, but in the first instance, a dermatology referral is needed to confirm the diagnosis and ascertain the best form of treatment.
10015859
d
Refer for excision
QuestionChoice
This would not prove useful in the treatment of SCC.
10015860
e
Trial a oral course of low dose steroids
QuestionChoice
This may be indicated in the treatment of the likely SCC, but in the first instance, a dermatology referral is needed to confirm the diagnosis and ascertain the best form of treatment.
10015858
c
Refer for cryotherapy
QuestionComment
My local trust has a current waiting list of up to 1 year for excisions 
54081
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subscriber
Maisie
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# Summary

An squamous cell carcinoma (SCC) is a malignant tumour of epidermal keratinocytes that is often locally invasive and can sometimes metastasise (unlike BCC, where this is rare). Key signs and symptoms include keratinised, scaly, irregular nodules that may ulcerate and display an everted edge. The key investigation method is an excision biopsy, and primary management involves surgical excision with possible adjunctive treatments like Mohs micrographic surgery or radiotherapy.

# Definition

An squamous cell carcinoma (SCC) is a locally invasive malignant tumour of epidermal keratinocytes. SCCs can cause pain, tenderness or bleeding and grow over weeks or months. SCCs sometimes metastasise, which can be fatal. By definition, since this is a cancer, there is invasion of the basement membrane.


# Risk factors

- Family history or previous history
- Genetic syndromes, for example Xeroderma Pigmentosum, an autosomal recessive condition that reduces the ability of the body to repair UV damage to DNA through nucleotide excision repair, essential for repairing the pyrimidine dimers formed from sun damage.
- Pale skin/light hair (always burns, never tans phenotype - Fitzpatrick type I or II skin)
- High levels of sun or UV exposure - for example through occupation, sunburn, or use of sun-beds
- Immunosuppression: where HPV viruses are thought to play a key role 
- Chronic inflammation - for example, a Marjolin ulcer, which is when a cutaneous SCC develops in the site of a chronically inflamed ulcer or scars 
- Predisposing lesions - these are pre-malignant lesions that occur due to sun-damage and may transition into SCC if not treated: 
	- Actinic (solar) keratosis: usually asymptomatic but can be mildly pruritic. They appear as scaly, keratotic, rough lesions, either plaques or papules. 
	- Bowen's Disease: also known as intraepidermal SCC or SCC in situ. Tumour cells are confined to the epidermis. Bowen's disease appears as an irregular, red, keratinised, scaly plaques.
- Smoking 
- Old age and male sex

	[lightgallery]
	
# Clinial Features

- SCCs of the skin can appear as keratinised, scaly, irregular nodules. On occasion, the keratin may be so developed that it forms a horn or a plug.
- They may be ulcerating, and have an everted edge
- Often in sun exposed areas. There may be background sun-damage, for example wrinkled skin and actinic keratoses. 
- The lesions may be polypoid
- The lesion is usually slow growing, over months
- Any complications are usually from local invasion; distant metastasis is rare, but can occur
- Pain, tenderness, and bleeding may be present

[lightgallery1]

# Investigations


- Diagnosis is usually made by excision biopsy with a 4mm margin (treatment and diagnosis at the same time, based on clinical suspicion) 
- Sometimes, a punch biopsy is the first investigation that is performed (for example if the lesion is especially large), later requiring an excision biopsy with a 4mm margin.
- A 6mm margin is required for high risk lesions, which are defined as:
	- 2cm+ diameter
	- Location on the ear, lip, face, hands, feet, or genitals
	- Elderly or immunosuppressed
	- Histological features: thicker than 2mm, poor differentiation, blood or nerve involvement, invasion of subcutaneous tissue
	

# Management

- Almost always treated surgically with excision using a 4mm margin (6mm for high risk lesions)
- Mohs micrographic surgery is sometimes used:
	- Tisue is removed and examined under a microscope in real time, to ensure that all the cancerous cells are removed but the maximum amount of healthy tissue is preserved. 
	- This is done especially if the area is ill-defined macroscopically, or if the area where the cancer is affecting is in need of preservation (for example, ear lobe or nose)
- Radiotherapy may sometimes be required
- Other options include curettage and cautery, topical 5-flourouracil, topical imiquimod, and cryotherapy if the lesion appears low risk (small, flat, and superficial), or in the case of suspected actinic keratoses or Bowen's disease
- Lifestyle advice to prevent further lesions (sun block)
- Plastic surgery input may be required if the lesion is particularly tricky to remove
- Prognosis is very favourable (a 5 year survival of 99%) if the SCC is detected early

# References

[Squamous cell carcinoma - DermNet NZ](https://dermnetnz.org/topics/cutaneous-squamous-cell-carcinoma)

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*An example of an ulcerated squamous cell carcinoma.*
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*An example of the appearance of Bowen's disease.*
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*An example of an ulcerated squamous cell carcinoma.*
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Squamous Cell Carcinoma
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A persistent, enlarging, hyperkeratotic and nodular skin lesion following unsuccessful treatment for an actinic keratosis may indicate squamous cell carcinoma, necessitating urgent dermatology referral.
Presentation
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Skin lesion
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Dermatology
A 76 year old man comes to the GP practice worried about a skin change. He has been diagnosed with an actinic keratosis on his scalp 2 years ago and has had topical 5-fluorouracil treatment and imiquimod for it, with no resolution. He says it has gotten bigger in the last 2 months. Inspection shows a nodular hyperkeratotic lesion.

What is the most appropriate course of action?
a