Squamous cell carcinoma of the skin occurs in keratinocytes, which are located in the epidermis.
Second most common non-melanoma skin cancer worldwide, secondary to basal cell carcinoma.
Cumulative ultraviolet exposure and immunosuppression are major risk factors.
Treatments include non-surgical destruction (e.g., using cryotherapy), topical and systemic chemotherapy, traditional surgical excision, and Mohs micrographic surgery.
Cutaneous squamous cell carcinoma (SCC) is the proliferation of atypical, transformed keratinocytes in the skin with malignant behaviour. It ranges from in situ tumours (also known as Bowen's disease) to invasive tumours and metastatic disease. Precursor lesions for SCCs are called actinic (or sun-damage) keratosis.
History and exam
Key diagnostic factors
- presence of risk factors
- growing tumours
Other diagnostic factors
- previous skin cancer
- evidence of sun damage to skin
- tender or itchy non-healing wound originally caused by trauma
- erythematous papules or plaques
- thin, flesh-coloured or erythematous plaques
- dome-shaped nodule
- exophytic, fungating, verrucous nodules or plaques
- ulcerated tumours
- bone pain
- neurological signs
- ultraviolet radiation exposure
- solid organ transplant recipient
- Fitzpatrick skin phototype
- hereditary skin conditions
- older age
- male sex
- ionising radiation
- actinic keratosis
- previous skin cancer
- human papillomavirus
- tobacco smoking
- thiazide diuretics and cardiac drugs
1st investigations to order
Investigations to consider
- CT body scan
- MRI scan
- PET scan
- FBC with differential
- chest x-ray
- non-invasive imaging technologies
SCC in situ (Bowen's disease)
immunocompromised or high risk of metastatic disease
Keyoumars Soltani, MD
Department of Medicine
Director of Immunopathology
Laboratory Section of Dermatology
The University of Chicago
KS declares that he has no competing interests.
Adaobi Nwaneshiudu Obasi, MD, PhD, FAAD
Medical Director, Dermatologist, and Dermatopathologist
Cutis Wellness Dermatology & Dermatopathology, PLLC
University of the Incarnate Word
Department of Family Medicine
ANO has received honorarium for lectures at 2020 Cynosure and PCCA meetings.
Prof K. Soltani and Dr A. I. Nwaneshiudu would like to gratefully acknowledge Dr Carlos Paz and Dr Jessica M. Sheehan, the previous co-contributors to this topic.
CP and JMS declare that they have no competing interests.
Nanette Silverberg, MD
Clinical Professor of Dermatology
Columbia University College of Physicians and Surgeons
New York City
NS declares that she has no competing interests.
Iris Aronson, MD
Department of Dermatology
University of Illinois
IA declares that she has no competing interests.
Keyvan Nouri, MD
Professor of Dermatology & Otolaryngology
Director of Mohs, Dermatologic & Laser Surgery
Director of Surgical Training
Department of Dermatology & Cutaneous Surgery
University of Miami
KN declares that he has no competing interests.
Jane McGregor, MA, MB, BChir, MRCP, MD
Senior Lecturer and Honorary Consultant Dermatologist (Barts and the London NHS Trust)
Institute of Cellular and Molecular Science
JMG declares that she has no competing interests.
- Actinic keratosis
- Basal cell carcinoma
- Seborrhoeic keratosis
- NCCN clinical practice guidelines in oncology: penile cancer (squamous cell carcinoma)
- NCCN clinical practice guidelines in oncology: squamous cell skin cancer
Skin cancer (squamous cell)
Staying safe in the sunMore Patient leaflets
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