Bowen's disease

Most cases of SCC in situ develop as a result of long-term sun exposure.  People who have a weakened immune system and are on long term immunosuppression medication are more likely to get SCC in situ. Very occasionally, SCC in situ may develop after radiotherapy, longstanding arsenic ingestion (very rare nowadays) or due to the human papillomavirus (a common virus that can cause viral warts). SCC in situ is not infectious and is not caused by an allergy.

Is squamous cell carcinoma in situ hereditary?

No, but some of the factors that increase the risk of getting it, such as a fair skin and a tendency to burn in the sun, do run in families.

What are its symptoms?

Often there are no symptoms, although the rough surface may catch on clothing.

A patch of SCC in situ starts as a small red scaly area on the skin, which grows very slowly. It may reach a diameter of a few centimetres across. It commonly occurs on skin that has been exposed to the sun, especially the face, scalp, and neck, as well as the hands and lower legs. There may be more than one area of skin affected. The development of an ulcer, lump or pain within a patch, may indicate the formation of invasive squamous cell cancer.

Images DermNetNZ.

From now on, you should take precautions to prevent additional patches of squamous cell carcinoma in situ developing:

Top sun safety tips

Sun protection is recommended for all patients. It is advisable to protect the skin from further sun damage (for example, by wearing a hat, long sleeves and a sunscreen with a high sun protection factor).

Routine sun protection is rarely necessary in the UK for people of colour, particularly those with black or dark brown skin tones. However, there are important exceptions to this; for example, sun protection is important if you have a skin condition, such as photosensitivity, vitiligo or lupus, or if you have a high risk of skin cancer, especially if you are taking immunosuppressive treatments (including organ transplant recipients) or if you are genetically pre-disposed to skin cancer. Outside of the UK in places with more extreme climates, you may need to follow our standard sun protection advice.

Vitamin D advice

The evidence relating to the health effects of serum vitamin D levels, exposure to sunlight and vitamin D intake, is inconclusive. People who are avoiding (or need to avoid) sun exposure may be at risk of vitamin D deficiency and should consider having their serum vitamin D levels checked. If the levels are low, they may consider:

• taking vitamin D supplements of 10-25 micrograms per day
• increasing intake of food rich in vitamin D such as oily fish, eggs, meat, fortified margarine and cereals.

A patch of squamous cell carcinoma in situ can look rather like other scaly skin conditions, such as psoriasis. For this reason, it is often examined under a dermatoscope (a magnifying tool used to examine the skin). Sometimes a biopsy (a small sample of skin) may be taken to make the diagnosis.

Can it be cured?

Yes. SCC in situ is confined to the surface of the skin and there are a variety of ways in which it can be removed (see below).

How can it be treated?

Several treatments are available for Bowen disease: