Cutaneous Squamous Cell Carcinoma (cSCC): Dysplasia to Invasion
Published: 04 August 2020
Published: 04 August 2020
While cSCC is a less serious form of skin cancer than melanoma, it can grow quickly and spread, causing potentially serious complications if untreated (CCV 2018; Mayo Clinic 2019).
However, If addressed early, cSCCs can be easily resolved in most cases (Skin Cancer Foundation 2020).
cSCC has several features distinguishing it from BCC and melanoma. Awareness of these differences can assist with timely referral and treatment, thereby reducing morbidity associated with aggressive tumours and enhancing overall patient outcomes. All healthcare professionals should be able to identify lesions and refer appropriately.
cSCC is triggered by DNA mutation (caused by UV radiation or other factors) to the flat cells located in the upper layer of the epidermis, known as squamous cells. This mutation causes the squamous cells to grow and divide abnormally. cSCCs grow quickly over weeks or months (CCV 2018; Skin Cancer Foundation 2020; Healthdirect 2018).
Squamous cells can be found in many parts of the body, all of which are susceptible to developing cSCC. However, in most cases, cSCCs appear on areas of skin that are most frequently exposed to UV radiation (Healthdirect 2018). These include:
(Oakley 2015)
Bowen’s disease is a pre-cancerous form of cSCC that generally presents as a red, scaly patch. If unaddressed, it may develop into cSCC (Healthdirect 2018).
Note: While ‘cutaneous squamous cell carcinoma’ specifically refers to cancer of the skin, squamous cell cancers can also develop internally (e.g. in the mouth, throat or lungs). These are known as ‘squamous cell carcinoma (SCCs)’ (Skin Cancer Foundation 2020).
Location of origin | Common physical characteristics | Growth and spread rate | Image | |
cSCC | Squamous cells (upper layer of the epidermis) |
|
Grow and spreads quickly; generally not serious but can cause complications if untreated. | ![]() |
BCC | Basal cells (bottom layer of the epidermis) |
|
Grows slowly and is unlikely to spread; least serious type of skin cancer. | ![]() |
Melanoma | Melanocytes (pigment-making cells in the epidermis) |
|
Grows and spreads quickly; most serious type of skin cancer. | ![]() |
(CCV 2018; American Cancer Society; 2019; SunSmart 2018)
There are about 777 000 new cases of cSCC and BCC in Australia every year, with cSCC accounting for about 30% of this figure. cSCCs most commonly affect people over the age of 50 (CCV 2018).
cSCC and BCC combined cause about 560 deaths annually (CCA 2019).
(Skin Cancer Foundation 2020; Mayo Clinic 2019)
About 90% of cSCC cases can be attributed to UV exposure (Skin Cancer Foundation 2020).
There are a number of signs to look for when identifying potential cSCCs as they can present in a variety of ways. Surface changes may include:
(Skin Cancer Foundation 2020; Mayo Clinic 2019)
The lesion will generally range between a few millimetres to several centimetres in diameter and might be inflamed or tender (Oakley 2015).
Dysplasia is the abnormal growth of a pre-existing lesion, from which cSCCs can develop. Initially, dysplastic keratinocytes above the epidermal basal layer behave abnormally, resulting in a focally thickened stratum corneum (SC); i.e. an actinic keratoses (AK) (Ratushny et al. 2012).
If the atypical keratinocytes demonstrate advancing dysplasia and dysfunction that fully infiltrates the epidermis, this becomes cSCC in situ, Bowen’s disease or intraepidermal carcinoma. A specific histological definition can highlight the lesion’s level of abnormality (Ratushny et al. 2012).
Well-differentiated cSCC’s most closely resemble normal tissue and are more predictable in behaviour than moderately well or poorly differentiated cSCCs, which are the most unpredictable tumours with poorer outcomes (Ratushny et al. 2012).
These less dysplastic, well-differentiated lesions retain some normal tissue function and can produce keratin, which may appear initially as a cutaneous horn (spiky, hard and often painful to the touch) (Ratushny et al. 2012).
A cSCC can be diagnosed through physical examination and biopsy if required (Mayo Clinic 2019).
The severity of the cSCC will dictate the appropriate treatment option. cSCCs and other cancers are often categorised using a staging system known as tumour-node-metastasis (TNM), which assesses three aspects of the cancer (EdCaN 2014):
(O’Brien 2017)
A comprehensive explanation of the TNM staging system can be found on the Cancer Council Australia website.
Treatment of cSCCs aims to completely remove the tumour in order to avoid recurrent disease or metastasis.
Depending on the patient’s characteristics, low-risk tumours (e.g. well defined, well-differentiated, small, thin and well-sited) can be treated with destructive modalities like curettage, cautery or topical creams.
High-risk tumours require complete excision. Challenging sites, e.g. thick, invasive lesions and lymph node involvement require a referral for comprehensive management (Skin Cancer Foundation 2020).
While cSCCs are not usually difficult to treat if addressed early, they have the potential to cause complications if left alone. Therefore, nurses working in all healthcare settings should have up-to-date knowledge of tumour types so that they can promptly identify cSCCs and determine the appropriate treatment for the patient.
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Question 1 of 3
Which of the following is NOT typically a physical feature of cSCC?
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Jan Riley is a specialist dermatology nurse based in regional New South Wales, Australia. Her postgraduate studies include a Certificate in Dermatology Nursing (USA), Master of Nursing (NP) and Certificates in Dermoscopy and Skin Cancer Medicine. Driven by a passion for “all things skin”, Jan is a staunch and passionate mentor and advocate, who is always ready and willing to share knowledge and inspire nurses to understand skin’s impact on daily lives. Her active participation in a range of professional activities has greatly assisted to raise the profile of dermatology and skin disease in the community. Jan currently develops and presents skin education modules through a co-directed nurse education company (Dermatology Nurse Education Australia) for nurses across all areas of care delivery. See Educator Profile
Ausmed’s Editorial team is committed to providing high-quality and thoroughly researched content to our readers, free of any commercial bias or conflict of interest. All articles are developed in consultation with healthcare professionals and peer reviewed where necessary, undergoing a yearly review to ensure all healthcare information is kept up to date. See Educator Profile