By Dr Ananya Mandal, MD
Skin cancers originate with common symptoms like abnormal growth in the skin, abnormal changes in existing moles and refusal of existing sores and ulcers on the skin to heal.
Most skin cancers can be found early with skin exams. Skin examinations need to be done regularly at home in susceptible individuals (who have more than one risk factor).
Steps in diagnosis of skin cancer
Diagnosis includes the following steps:-
Self examination of the skin is an early method by which skin cancers can be detected early. Self examination should be performed at least once a month.
Self examination should be done in front of a full length mirror in a well-lit room. A smaller hand-held mirror can be used to look at areas that are hard to see. All individuals must be aware of the normal appearance of moles, scars and marks over their skin. This would alert them if there is any change in moles, freckles, or marks over the skin.
The first part includes checking face, ears, neck, chest, and abdomen. Women should lift their breasts to check underneath. Thereafter underarms, arms, tops and bottoms of hands, between fingers and under fingernails should be checked. Next the thighs, shins, feet, soles, in between toes and under toenails should be examined. Using a hand held mirror back of the legs, knees, thighs, buttocks, genital area, lower and upper back, back of the neck and ears, scalp etc. need to be checked.
Basal cell cancers and squamous cell cancers are commonly found in areas of skin exposed to the sun but they can occur elsewhere. One should look for patches, or non healing sores, marks, growths and abnormal moles. A normal mole has an even coloring of brown, tan, or black. The size is usually less than a quarter inch (size of a pea) and can be either flat or raised. It can be round or oval.
A mole can be present at birth, or it can appear during childhood or young adulthood. Moles appearing later in life need to be checked.
Moles usually remain the same shape and size and color throughout life. Some moles may also fade away with age. The most important warning sign for melanoma is abnormality in a mole.
Physicians usually look for the ABCDE symptoms to diagnose a melanoma. These include:-
Asymmetry of the mole
Altered or increased Diameter
Evolving or changing
A detailed medical history of sun exposure, sun burns and family history of melanoma and skin cancers is obtained to ascertain the risk of skin cancers.
Lymph node swelling
Local lymph nodes are examined for swelling. Melanomas can spread to other organs via lymphatic channels.
A skin disease specialist or a dermatologist will next use dermoscopy or epiluminescence microscopy [ELM], surface microscopy, or dermatoscopy to see spots on the skin more clearly. This device is essentially a special magnifying lens with a light source that is held near the skin. A thin layer of oil may be used with this instrument. A digital or photographic image of the spot may be taken.
If the spot appears suspicious the dermatologist may prescribe a skin biopsy to confirm the diagnosis of skin cancer. Different methods can be used for a skin biopsy. For a biopsy a small sample of skin is taken and the sample is sent to the lab. A pathologist looks at microscopic preparations of the sample under the microscope.
Biopsies are usually performed under local anaesthesia. There are some common types of skin biopsies. These include a shave biopsy where a thin slice of the tissue is shaved off from the lesion. For a deeper examination a punch biopsy, an incisional or an excisional biopsy may be undertaken.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)