Skin cancer is differentiated based upon the type of skin cell that’s involved.
There are three main types of skin cancer: basal cell carcinoma, squamous cell carcinoma - collectively known as non-melanoma skin cancer, and melanoma.
Diagnosis of skin cancer starts with naked-eye skin examination of the characteristics of the lesion, as well as detailed history of the current skin complaint, asking for the time of onset, duration, location, evolution, and symptoms.
This is then followed by dermoscopy. Dermoscopy is a noninvasive, in vivo technique used for the evaluation of skin lesions.
It allows for the visualization of subsurface skin structures in the epidermis, dermoepidermal junction, and upper dermis, which are otherwise not visible to the naked eye.
There are three dermoscopic criteria to predict malignancy of a pigmented lesion - asymmetric distribution of colors and structures within a lesion, blue-white structures, and atypical network.
On the other hand, for nonpigmented lesions, the three criteria are ulceration, white zones, and vascular structures and patterns.
Now, the main purpose of dermoscopy in the evaluation of pigmented and nonpigmented skin lesions to help decide whether or not to monitor the lesion over time with sequential digital dermoscopy imaging to determine its biologic nature, or to perform a skin biopsy, which is needed to confirm diagnosis of skin cancer, showing the type of cells involved.
Biopsy can also serve as the definitive treatment for lesions that haven’t spread elsewhere.
The three main types of skin biopsy are shave biopsies, punch biopsies, and excisional biopsies.
In shave biopsies, a superficial thin piece of skin is removed from the surface using a small sharp blade, so they are typically used for lesions for which sampling of the full thickness of the dermis is not necessary.