Skin cancer occurs when there is an overgrowth of a certain cell type that makes up the skin. There are several types of skin cancer with the most common being pre-skin cancers or actinic keratoses, basal call carcinoma, squamous cell carcinoma and melanoma. Other more rare types of skin cancers may also occur such as merkel cell, cutaneous t-cell lymphoma, etc.
A pre-skin cancer is when a cluster of atypical cells is just sitting on the surface of the skin and we refer to them as actinic keratoses. Approximately 1-10% of these have the potential to develop into skin cancers. They can be easily treated by your dermatologist with various modalities including, but not limited to, liquid nitrogen, photodynamic therapy, topical imiquimod, topical 5-flurouracil.
A basal cell carcinoma (BCC) is an overgrowth of the cells that make up the basal layer of the epidermis. BCC has various subtypes depending on it’s growth pattern. It may be superifical creating a pink scaling spot on the surface of the skin, or it may be nodular or microdoular forming collections of the skin cancer cells in the skin of various sizes. It may also be sclerosing or infiltrative where it forms scars and has finger –like projections that dive into the skin. Treatment options for BCC depend on the subtype, size and location of the skin cancer. Treatment modalities range from topical imiquimod, electrodessication & curettage, excision or Mohs Micrographic Surgery. If left untreated, these do not typically resolve on their own and continue to destroy skin and tissue and can develop ulcers or sores in them that bleed. They also have the potential to break off and spread or metastasize, although this is not as common.
A squamous cell carcinoma (SCC) is made of cells that make up the skin called squamous cells. The squamous cell is a type of cell that is also found in other tissues such as the lining of the lung, etc. SCC in skin behaves much differently than SCC in the lung or other organs. A squamous cell carcinoma that just is sitting on the top layer of the skin (epidermis) is called a SCC in situ. These can be treated with electrodessication and curettage. If they have become more invasive or travel down a hair follicle then excision or Mohs Micrographic surgery is indicated. Some SCC’s can be more aggressive and can invade the nerve (perineural invasion) and may break off and metastasize.
A melanoma is when a mole made of melanocytes has become cancerous. These can also just be located in the very top layer of the skin (epidermis) and are referred to as melanoma in situ. When melanoma is caught in this early stage, it has the highest cure rate. When it progresses deeper into the skin the risk of metastasizing greatly increases. When a melanoma is more than 1mm in depth and sometimes 0.76mm in depth, the suspicion for metastases increases and a sentinel lymph node biopsy is performed. Your dermatologist and/or oncologist may also advise further evaluation for metastatic melanoma.