The skin is composed of an outer layer called epidermis, which contains squamous cells, basal cells and melanocytes.
The dermis is the deeper layer of the skin and contains hair follicles, oil and sweat glands and blood vessels. Skin cancers can arise from any of these cells, each type having a characteristic clinical appearance, however, a biopsy (sampling) is usually required to confirm the diagnosis of skin cancer.
Fair skinned individuals develop skin cancers far more frequently than darker skinned people. Excessive exposure to sun is the single most important factor associated with skin cancer of the face, eyelids and arms. Skin cancers can also be hereditary.
The most common type of skin cancer seen in the periocular (eye) area is basal cell carcinoma (BCC). This cancer arises from the basal cells & is also called a “rodent ulcer” as it grows very slowly.
The second most common skin cancer in the periocular area is squamous cell carcinoma (SCC), this is a more serious form of cancer than BCC, as it can spread to other parts of the body (metastasize). Either may appear as a painless nodule, or a sore, that won’t heal. The skin may be ulcerated, or there may be bleeding, crusting or distortion of the normal eyelid structure and loss of eyelashes.
Melanomas arise from pigment producing melanocytes, and are a less common but more serious form of skin cancer. A mole that bleeds, becomes tender, changes size, shape or colour needs to be seen urgently by a physician.
Sebaceous gland carcinoma is a more serious but rare form of skin cancer. It may appear as a recurrent chalazion, persistent eyelid inflammation, chronic red eye or thickening of the eyelid.
Melanoma and sebaceous gland carcinomas can metastasize to other parts of the body through the blood stream or lymphatic system. Prompt, aggressive treatment is necessary because of risk of early spread.”