Understanding Your Melanoma Diagnosis: 

Melanoma In Situ 

Dr. Chris Irwin

 

Being diagnosed with melanoma can be scary, but the good news is that the type of melanoma you have is very early-stage and can be completely cured. This handout explains melanoma in situ —and why it does not require additional tests like lymph node biopsies or body scans. We’ll also discuss what to expect next and how these early melanomas are managed in a patient-friendly way!

Melanoma In Situ (Stage 0)

Melanoma is a cancer of pigment cells (melanocytes) in the skin.

Figure 1. Histological diagram of a melanoma in situ.

Image from mypathologylab.ca (https://www.mypathologyreport.ca/diagnosis-library/melanoma-in-situ/)

Melanoma in situ means the cancer cells are confined to the very top layer of the skin (the epidermis). It is sometimes called Stage 0 melanoma. In plain language, it means the melanoma “hasn’t started digging deeper into the skin” yet. The “in situ” part just means that it is still “in place” – ie. that it is still in the epidermis only and hasn’t learnt to invade yet. 

The skin contains two basic parts. The epidermis is the top layer of skin and the bottom layer of skin is called the dermis. The epidermis and dermis are separated by a very tough canvas like layer called the basement membrane or “dermo-epidermal junction”. If a cancer has not yet learnt how to get through this tough canvas layer, that means it has no way of travelling to other parts of the body (metastasis). This is because all of the highways that cancers use (eg. veins, arteries and lymph vessels) are all only in the dermis. There are no highways in the epidermis. This is great because it means if we cut it out properly with good margins, the cancer can essentially be cured with no risk of metastasis and very low risk of recurrence.

No lymph node biopsy or scans needed: Since it cannot spread to lymph nodes or organs (it hadn’t reached those deeper channels), no further tests like lymph node biopsies, CT scans, or PET scans are needed. Your doctors know the melanoma was only on the surface, so surgery is the only treatment necessary. 

 

Follow-up

 The main follow-up for melanoma in situ is regular skin checks. Every doctor’s practice is different. We know that a patient who has been diagnosed with one melanoma has a 9x greater risk of developing a second melanoma compared to a matched control (Bradford  PT, Freedman  DM, Goldstein  AM, Tucker  MA.  Increased risk of second primary cancers after a diagnosis of melanoma.  Arch Dermatol. 2010;146(3):265-272.) and this is greatest in the first two years after diagnosis.) For the first two years I tend to see my patients every 3 months, after that gradually extending out further reviews to every 6-12 months on a case by case basis.

• No Routine Scans or Blood Tests: As discussed, you won’t be undergoing regular CT/PET scans or blood work for melanoma markers, because there’s no indication to do so. Don’t be alarmed by the lack of testing – it truly is a positive sign about your prognosis. 
• Scar Care: You will have a scar from the surgery. Keep it clean and protected from the sun as it heals. Over time (months to a year) it will fade and soften. 

You can help minimise the scarring by using a silicone gel called strataderm twice a day for 3 months. We will chat more about the specific restrictions for your specific wound.

 

Another technique to reduce scarring is to keep the wound dressed for as long as possible after surgery. This sounds like a lot more effort than it is – after the initial sutures come out our nurses will show you how to dress the wound with MEFIX. This is a breathable dressing that you can get wet, pat dry and essentially just treat as a second skin. What this dressing does, is every time you move the area over the next 6-12 weeks, the dressing takes some of the stretch instead of making the scar stretch a little. You change the MEFIX every 5-7 days depending on activity level, soak it off with a little bit of olive oil (or just in the shower) and gently peel it off, before drying the skin and applying another MEFIX dressing. The longer you do this for the better the wound will be. In general for facial wounds we recommend the silicone gel due to its ease of use.

Scarring is inevitable but I try my absolute best to give you the best scar possible using the best suturing techniques. 

 

• Sun Protection: One of the best ways to prevent future skin cancers is to practice good sun safety. That means using sunscreen (SPF 50) on exposed skin daily, wearing hats and protective clothing when in strong sun, and avoiding indoor tanning. 
• Peace of Mind: It’s normal to feel anxious after a cancer diagnosis, even one as low-risk as this. Remember that your melanoma was caught at a very early stage. If you find yourself worrying a lot, consider discussing these feelings with your doctor. Sometimes connecting with a counselor or a support group of melanoma survivors can be helpful. Knowing others have gone through the same thing and are doing fine can be very helpful.

Takeaway: *Melanoma in situ is the earliest possible melanoma stage. It’s removed with minor surgery and has almost zero risk of spreading anywhere​. No further tests (like scans) are required because the melanoma was caught before it could go anywhere. The main important thing moving forward is that we need to be super vigilant ongoing because you are at high risk of developing further melanomas.