These are procedures that are sometimes performed for advanced cases of skin cancer, e.g.; Lymphatic clearance (Neck, Axillary & Groin Dissection) which removes lymph glands that are involved with the disease. A Sentinel Node Biopsy is a procedure used to identify lymph node involvement. In this procedure, a dye is injected into the surgical / skin cancer site which will be picked up by the lymph gland responsible for draining that particular area of skin, thus helping identify cancer cells that may have travelled and spread away from the original site.
The photo below shows a blue dye picked up by a lymph node in the Axilla.
