Should I worry about melanoma in situ?
Sophia Vance
Published Jan 15, 2026
In situ melanomas don't spread to other parts of the body or cause death, but if the tumor has an opportunity to grow even one millimeter deep into the skin, it can lead to more involved treatment and greater danger. If left untreated, it can metastasize and even become life-threatening.
Is melanoma in situ really cancer?
Melanoma in situ is also called stage 0 melanoma. It means there are cancer cells in the top layer of skin (the epidermis). The melanoma cells are all contained in the area in which they started to develop and have not grown into deeper layers of the skin. Some doctors call in situ cancers pre cancer.What is the prognosis for melanoma in situ?
Prognosis: Stage 0 melanoma, or melanoma in situ, is highly curable. There is very little risk for recurrence or metastasis. The 5-year survival rate as of 2018 for local melanoma, including Stage 0, is 98.4%.How long does melanoma in situ take to spread?
The lesion can grow slowly for 5 to 15 years in the in situ form before becoming invasive. The exact percentage of lentigo maligna lesions that progress to invasive lentigo maligna melanoma is unknown but is estimated to be less than 30% to 50%.Does all melanoma in situ become invasive?
It is thought that less than 5% of lentigo maligna and lentiginous melanoma transform into invasive melanoma. The risk of melanoma in situ evolving into invasive melanoma over time is greater in superficial spreading melanoma, acral lentiginous melanoma and other forms of melanoma, but the exact risk is unknown.Skin Cancer Melanoma in situ
Is early evolving melanoma in situ reportable?
early or evolving invasive melanoma, ARE NOW REPORTABLE! Per SEER, for cases diagnosed January 1, 2018 forward, early or evolving melanomas of any type are NOT REPORTABLE. This includes ANY invasive and/or in situ melanomas described as early or evolving.What is the best treatment for melanoma in situ?
Stage 0 melanoma (melanoma in situ) has not grown deeper than the top layer of the skin (the epidermis). It is usually treated by surgery (wide excision) to remove the melanoma and a small margin of normal skin around it.How thick is melanoma in situ?
This stage is also known as melanoma in situ. The tumor is more than 1 mm thick (T2b or T3) and may be thicker than 4 mm (T4). It might or might not be ulcerated. The cancer has not spread to nearby lymph nodes (N0) or to distant parts of the body (M0).Can you live 20 years with melanoma?
Survival for all stages of melanomaGenerally for people with melanoma in England: almost all people (almost 100%) will survive their melanoma for 1 year or more after they are diagnosed. around 90 out of every 100 people (around 90%) will survive their melanoma for 5 years or more after diagnosis.