What is Intraepidermal Carcinoma?
“Intraepidermal” refers to cancer cells found within the epidermis, which is the outer layer of your skin. These cancer cells develop in the very place they were formed, a situation described medically as “in situ”. A mild form of this situation is squamous cell carcinoma in situ (SCCIS), where the cancer cells grow superficially on the surface of the skin.
It’s important to stress that this condition isn’t severe, but it can evolve into full-blown skin cancer if it’s not discovered early or if it’s not properly treated. This condition is referred to in medical terminology as ‘carcinoma in situ’ or ‘Bowen disease’, named after John T. Bowen, an American skin doctor who first identified the condition in 1912.
The cells affected by this condition are called squamous cells. These are flat cells found in the epidermis, and they are responsible for the production of a protein called keratin, a key substance found in our skin, hair, and nails.
What Causes Intraepidermal Carcinoma?
Squamous cell carcinoma in situ, a type of skin cancer that affects the topmost layer of the skin, was first linked to radiation exposure in 1920. However, studies nowadays show that the most common cause of this cancer is long-term exposure to sunlight on unprotected skin. Sunlight contains ultraviolet radiation that can damage the genetic material in skin cells, causing mutation in a specific gene named p53. This mutation can lead to the rapid increase of skin cells.
Sunlight’s ultraviolet (UV) rays can also hinder skin cells’ natural ability to repair themselves. Furthermore, diseases or medications that weaken the immune system can cause skin cells to mutate and potentially lead to cancer. Other factors contributing to the development of squamous cell carcinoma include ingestion of arsenic and certain viral infections.
Risk Factors and Frequency for Intraepidermal Carcinoma
A 1991 study from Minnesota looked into the occurrence of squamous cell carcinoma (SCC) in the US. The study found that on average, there were 14.9 cases of SCC per 100,000 white people each year. By 1994, this number had increased tenfold. This disease generally occurs more often in white individuals, with very few cases in people with dark skin. SCC affects both men and women equally and usually appears in middle-aged to elderly individuals.
- A study from Minnesota in 1991 found an average of 14.9 cases of SCC per 100,000 white people each year.
- By 1994, the rate of SCC had increased tenfold.
- People with white skin are most commonly affected by this disease.
- People with dark skin rarely have SCC.
- The disease equally affects both men and women.
- SCC usually occurs in individuals who are middle-aged to elderly.
Signs and Symptoms of Intraepidermal Carcinoma
Squamous cell carcinoma in situ (SCCIS), also known as Bowen’s disease, is a type of skin cancer that typically affects areas of the skin exposed to the sun, like the head and neck. However, it can also appear on the body. In the early stages of Bowen’s disease, the skin shows red, scaly patches, which are viral lesions. As the disease progresses, these patches can develop into lumps or sores that may break open and form ulcers.
Testing for Intraepidermal Carcinoma
A skin biopsy is the best way to diagnose a carcinoma in situ, which is an early stage skin cancer that is only in the upper layer of the skin. Two types of skin biopsies can be used. A shave biopsy is when a small piece of the top layer of skin is shaved off. A punch biopsy is when a small, circular tool is used to remove a deeper sample of skin. The samples should be taken not just from the area where skin cancer is suspected, but also from the surrounding skin. These samples are then looked at by a dermatopathologist, which is a specialized doctor who interprets skin samples under a microscope.
For those suspected of having squamous cell carcinoma in situ, a specific type of skin cancer, it’s necessary to have a complete examination of the skin. This should be done on all areas of the skin, whether exposed to the sun or not. This comprehensive check is important because it can help identify other potential areas of concern.
Treatment Options for Intraepidermal Carcinoma
The standard way to treat this type of skin cancer is to carefully examine the tumor under a microscope and then remove it through minor surgery. Other treatments that skin doctors might suggest, especially for early-stage growths, involve the use of creams like imiquimod or 5-fluorouracil. Both of these medications work to strengthen the body’s immune response against the cancerous cells.
Sometimes, a special kind of X-ray called Grenz-ray radiation therapy may be recommended, particularly for patients with several growths. Another promising method is photodynamic therapy. This treatment involves injecting a substance that is absorbed by the tumor. Once absorbed, a light is shone on the area, which activates the substance and helps to destroy the tumor.
It’s important to remember that the best treatment plan will vary depending on individual circumstances like the size of the tumor, its location, and the patient’s overall health.
What else can Intraepidermal Carcinoma be?
If you have a certain set of symptoms, it might suggest you have squamous cell carcinoma in situ, which is a type of skin cancer. However, these symptoms can also be signs of other conditions, so it’s crucial to get the right diagnosis. The conditions that can be confused with squamous cell carcinoma in situ include:
- Atopic dermatitis (a type of eczema)
- Pyoderma gangrenosum (a rare skin condition that causes painful sores)
- Bowenoid papulosis (a skin condition that can look like warts)
- Atypical fibroxanthoma (a skin tumor)
- Melanoma in situ (the earliest stage of skin cancer)
- Paget disease (a type of breast cancer)
Therefore, it’s essential to have a thorough check-up and get the correct diagnosis.
What to expect with Intraepidermal Carcinoma
The chances of the disease turning into invasive squamous cell carcinoma, a type of skin cancer, are quite low, around 3% to 5%. A study, while noting that some biases may exist, reported that amongst the 3% to 5% who developed invasive squamous cell carcinoma, one-third could possibly spread the cancer to other parts of the body. Conditions like erythroplasia of Queyrat or genital Bowen disease pose a higher risk comparatively.
After surgery meant to remove the carcinoma completely, if any part of the disease remains, there can be a risk of the condition returning.
