Dysplasia to Invasion: Squamous Cell Carcinoma (SCC)
Published: 08 May 2016
Published: 08 May 2016
Squamous cell carcinoma (SCC), the second most common non-melanoma skin cancer (NMSC), has several features distinguishing it from basal cell carcinoma (BCC). Awareness of these differences can assist with timely referral and treatment, thereby reducing morbidity associated with aggressive tumours and enhancing overall patient outcomes. Therefore, all healthcare professionals should be able to identify lesions and refer appropriately.
SCC is caused by a range of factors, including:
There are a number of things to look for when identifying potential SCCs. Surface changes may include:
Dysplasia is the abnormal growth of a pre-existing lesion, from which SCCs 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).
If the atypical keratinocytes demonstrate advancing dysplasia and dysfunction that fully infiltrates the epidermis, this becomes SCC in situ, Bowen’s disease or intra epidermal carcinoma. Specific histological definition can highlight the lesion’s level of abnormality. Well differentiated SCC’s most closely resemble normal tissue and are more predictable in behaviour than moderately well or poorly differentiated – the most unpredictable tumours with poorer outcomes. 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.)
Careful diagnosis of lesions thick or larger than 2cm, previously treated (recurrent), or biopsy results showing suspected perineural invasion, will dictate appropriate therapy. It’s important to note that tumour sites around the ear or cheek, cases of immunosuppression and other high risk tumours displaying increased risk of metastasis and local tissue involvement, can cause death. Metastatic disease can also result from poorly treated, advanced or neglected tumours.
Treatment of SCCs aims to completely remove the tumour in order to avoid recurrent disease or metastasis. The appropriate mode of treatment is determined by biopsy. Depending on patient 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, thick, invasive lesions and lymph node involvement requires referral for comprehensive management.
In summary, it is imperative that nurses working in all health settings have up-to-date knowledge of tumour types, in particular squamous cell carcinomas.
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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.