Basal cell carcinoma

Basal cell carcinoma 

Updated: 03/17/2021

© Jun Wang, MD, PhD

General features
  • Most common skin cancer
  • Usually > 40 years of age
  • Multiple BCCs may develop early if nevoid basal cell carcinoma syndrome
  • Mainly sun exposed skin, especially hair-bearing areas
  • Slow growing, rarely metastasize
Risk factors
  • Exposure to natural and artificial ultraviolet light
  • Radiation
  • Gene mutations
  • Existing actinic keratosis
  • Arsenic exposure, immunosuppression, albinism, alcohol, xeroderma pigmentosum
Key pathogenesis
  • UV
UVB: most carcinogenic, absorbed by DNA
DNA damage and p53 mutation
  • DNA mismatch repair defect
  • PTCH mutation
Hedgehog pathway
Causes loss of inhibition of SMO, results in constant activation
Seen in nevoidbasal cell carcinoma syndrome, sporadic basal cell carcinomas and Xeroderma pigmentosum associated basal cell carcinoma
Clinical features
Key pathological features
Multifocal growth
Irregular budding from basal layer
  • Nodular type
Nodular growth of tumor cells
  • Morpheaform
Irregular cords or nests of tumor cells
Fibrotic stroma
Higher recurrence rate
Likely perineural invasion
Mohs surgery indicated
  • Other variant: basasquamous cell carcinoma, clear cell type, etc
Management
  • Excision
  • Radiation
  • Photodynamic therapy
  • Hedgehog pathway inhibitors



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