Skin Cancer Terms: Melanoma In Situ

by Anne Windermere Patient Advocate

When you or your loved one gets a diagnosis of skin cancer you may hear terminology which is new to you. The best person to ask about the meanings of terms used during your doctor visit is your doctor. Yet it can difficult to ask all the questions we want to because appointments can be rushed for time. Another reason we may not ask all of our questions is because we may be in shock and tend to only focus on the words, "skin cancer" to hear much else. We are here to help. In the next several posts we will be explaining some common skin cancer terms so you will have a better understanding of what your doctor is telling you.

The first skin cancer term we are going to cover is melanoma in situ. Melanoma
is the most deadly of skin cancers so when you hear this word with respect to your diagnosis, it may be difficult to hear anything else. But if your doctor adds the phrase, "in situ" it may be actually be better news than you think. Melanoma in situ means that the skin cancer cells are confined to the epidermis and have not spread. This is considered to be the earliest (stage 0) and most treatable form of melanoma skin cancer. Cure rates average 95% or more with treatment. Some sources say that patients treated for melanoma in situ have a nearly 100% survival rate at 5 and 10 years.

When the skin cancer cells have penetrated through the outermost layer of skin into the deeper layers (the dermis) then it is diagnosed as invasive melanoma. For more information about the different stages of melanoma skin cancer, The National Cancer Institute has extensive and detailed information about each phase of growth.

Treatment for Melanoma in Situ

The best person to ask about treatment options for your skin cancer is your doctor or dermatologist. They will know the best treatment for you. Patients with melanoma in situ are usually treated with surgical excision of the lesion. This surgical removal will usually cure the skin cancer at this stage. Your surgeon will try to remove the entire melanoma in situ with a 0.5 cm margin of healthy skin around the lesion. A pathologist will confirm that the excision is adequate and that there are no remaining cancer cells. If the lesion is not properly excised this can lead to a greater risk of recurrence or even progression of already existing cancer cells to penetrate deeper into the skin.

Risk of Recurrence and Prevention

When you have any type of skin cancer, recurrence is always a risk. As melanoma is the most deadly of all types of skin cancers, it is especially important that you seek the guidance of your doctor to prevent it from coming back. Despite the low risk of recurrence associated with stage zero melanoma (some studies show a 5% recurrence rate) it is wise to take preventive measures. Most skin cancer experts suggest that visiting your dermatologist or doctor every six months is a good idea if you have been diagnosed with melanoma in situ. Ask your doctor about the frequency of office visits appropriate for you.

Prevention of recurrence is based upon the same strategies used to prevent all skin cancers. In my post, How to Prevent Skin Cancer from Returning, I give some general guidelines of things you can do to minimize your risk of developing new lesions. Some of these strategies include performing a self skin exam
and following sun safety measures.

We have a lot of information about Melanoma on Skin Cancer Connection.
Here are just some of the articles you may find on this topic:

Anne Windermere
Meet Our Writer
Anne Windermere

These articles were written by a longtime HealthCentral community member who shared valuable insights from her experience living with multiple chronic health conditions. She used the pen name "Merely Me."