Squamous cell skin cancer


  • Tumour originating from the keratinocytes in the skin
  • Second most common skin cancer after BCC (accounts for ~20% of non-melanomatous skin cancer)
  • Incidence is rising.  Currently around 17 per 100,000 people per year (around 10,000 cases per year)

Risk Factors

  • UV exposure
  • Immunosuppression
  • Exposure to radiation or carcinogens
  • HPV infection (warts)
  • Fair (type I) skin
  • Chronic inflammation
  • Development from pre-malignant disease e.g. Bowen’s disease, actinic keratosis


  • Loss of function mutations in p53 (e.g. caused by UV-light)
  • Other genetic neoplastic changes e.g. mutations in BCL2, RAS and eGFR
  • Typical histological features include
    • nuclear atypia, frequent mitotic figures, cellular pleomorphism, hyper- and parakeratosis (retaining the nuclei in the stratum corneum), a disorganised progression of cells from basal to apical layers of the epidermis
    • SCC can be graded based on histology as
      • Well differentiated (normal looking nuclei with abundant cytoplasm and extracellular keratin)
      • Moderately differentiated
      • Poorly differentiated (many atypical nuclei and mitotic figures; >nuclear:cytoplasmic ratio; less keratinisation)


  • Usually on sun-exposed areas e.g. bald scalp, ears, face and hands
  • Variable presentation
    • from rapid development of a painful keratotic nodule
      • may be over an area of pre-existing dysplasia
    • to new, erythematous, infiltrated, warty nodule/plaque that can ulcerate
    • Usually, a slowly-growing, tender, scaly/crusted lump


  • Excisional biopsy is the management of choice for most patients
    • As with BCC, Mohs surgery can be considered for tumours that are high risk or those in difficult areas
    • Radiotherapy may be required in unresectable tumours
    • Cryotherapy is an option for small, well-defined and low risk tumours

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