Squamous Cell Carcinoma in situ (SCCis)

Squamous Cell Carcinoma (SCC) is an early form of skin cancer that can be cured with non-invasive treatments if caught early.

What is a Squamous Cell Carcinoma in situ (SCCis)?

A squamous cell carcinoma in situ is a superficial form of an SCC that is contained within the epidermis. There are numerous alternative names for them including Bowen’s disease and intraepidermal carcinoma (abbreviated as IEC). They develop from accumulated DNA damage due to repeated ultraviolet radiation (e.g. sunlight). They are the middle step on the SCC continuum:

  • Actinic keratosis (AK): the most superficial.
  • SCC in situ: limited to the epidermis.
  • SCC: invading the dermis.

SCCis are larger than actinic keratoses, but like AKs, they also appear as scaly lesions. Often they have red discolouration at the base of the lesion.

Treatment for a Squamous Cell Carcinoma in situ

Because they are superficial, there are several treatments available:

Diagram comparing cryotherapy, curettage and shave excision
Non invasive procedures cryotherapy shave excision and curettage


Because SCCis are superficial they won’t spread (metastasise) however, if they are left untreated they can progress to an SCC. SCCis can recur after treatment.

Photo of squamous cell carcinoma in situ (SCCis) on a finger.
SCCis on a finger
Dermoscopy photo of a squamous cell carcinoma in situ (SCCis).
Dermoscopy of SCCis