Advanced
Technical
IVT
melanoma in situ
Early-stage melanoma confined to the epidermis without invasion into deeper skin layers.
Full Definition
The earliest form of melanoma where malignant melanocytes are confined to the epidermis and have not invaded the dermis or deeper structures. Melanoma in situ has no metastatic potential as it has not gained access to blood vessels or lymphatics in the dermis. When completely excised with adequate margins, the cure rate approaches 100%. Different subtypes include lentigo maligna (on sun-damaged skin) and superficial spreading melanoma in situ (on non-sun-damaged skin).
Usage
Usage note: Always specify 'in situ' to distinguish from invasive melanoma.
In Context
- "Histopathology confirmed melanoma in situ with clear surgical margins." — pathology report
- "The patient's melanoma in situ was successfully treated with wide local excision." — surgical summary
Also known as
MIS
Contrasted with
invasive melanoma
Don't confuse with
atypical nevus
severely dysplastic nevus