Overview of Melanoma

The melanocytes or the pigment producing cells are naturally present in the skin, mucous membranes, eyes, gut, and meninges of the brain. An abnormal cancerous proliferation of melanocytes results in a melanoma. This aggressive cancer may start in the skin but quickly spreads to the lymph nodes and internal organs.

Melanoma forms 4% of all skin cancers but is leading (77%)cause of death among all cancers in the western world .Thousands of new cases are identified everyday and approximately 7700 patients per year die of melanoma.

The skin type 1 and 2 that is the white skins are the prototypes who are predisposed to this threatening cancer , a cumulative sun exposure with history of intermittent sunburns or an inability to tan and a personal or family history of melanoma or dysplastic nevus increases the risk of getting melanoma many fold. Also certain individuals on Ultraviolet a therapy (UVA) are at an increased risk.

UV radiation has been suggested as a major cause of malignant melanoma, because the incidence and mortality among Caucasians increases with proximity to the equator, where solar radiation is more intense. Further, it has been suggested for Caucasians that the increasing incidence of melanoma results from the increased exposure following changes in fashions of dress and sun-bathing.

Melanin granules exert a protective effect by absorbing UV, thereby preventing damage to the DNA of the melanocytes which accounts for reports of a low incidence of melanoma among dark-skinned races living in tropical latitudes .Blacks and Asians have 1/12th the risk of melanoma as whites.

According to the report of a study based on Volume II of the series Cancer Incidence in Five Continents a constant low incidence of melanoma was observed among the sub-groupings of Asian populations, with the highest incidence of melanomas among the Chinese and the lowest among the Indians.

However even though incidence of melanoma is less in pigmented skin the melanoma can still occur and for all those afflicted can die due to delay in early detection over a false sense of security ,for the survival rate in melanoma is directly related to early detection!

• 95% of melanomas are totally curable if detected and treated early.
• A previously benign mole may change into a melanoma if strong predisposition exists however not all melanoma develops from a changing mole. Melanoma can also appear on a totally normal skin where there was no a previous mole or appear as a nail streak or non-healing bruise.

The emphasis is now on patient education and awareness to be able to recognize a melanoma in its earliest stages

The ABCD sign of melanoma is the most widely followed guide to detect an early melanoma on an examination.

• Asymmetry of the lesion on skin
• Border irregularity in a skin lesion
• Color variability in a skin lesion
• Diameter >6mm

a Dermoscopic examination further with a epilumiscence microscopy supplements in judging whether one is dealing with a melanoma Change in a mole or if the mole is benign however the gold standard method of confirming a mole from a melanoma is a skin biopsy and microscopic examination which undoubtedly reflects the placement and proliferation of the pigment cells right from the epidermis to the fat cells. Also testing the lymph nodes by a biopsy also helps to find infiltration into them.

Prevention or risk reduction is the strategy followed world wide and the prevention is of 2 types.

Primary prevention is by public education and awareness, self examination, frequent dermatological evaluation and biopsy of suspected skin moles.
Secondary prevention includes teaching high risk patients about ABCD signs and total body self examination.
Also screening programmers and regular examination by health professionals play an important role

Acral lentiginous melanoma makes for 5% in white skins of all melanomas but is the most common form of melanoma seen in the Asians and dark skinned people and accounts for 50 % of all melonaoms seen in the Asians. It is also called as hidden melanoma because it occurs on parts of body not easily examined every day. Acral lentiginous melanoma can occur on palms ,soles , underneath finger and toe nails, mucous membranes like the lining of the mouth, the nose ,the genitalia and also urinary tract or anal lining,. On appearance it may look like a streak in the nail, a bruise, when on palms and soles it may appear like a pigmented brown or black irregular spot or like a dark bluish bruise on skin after a blow.Many individuals, especially dark-skinned people, have fixed nail streaks that are completely harmless. A new nail streak not associated with recent injury, an enlarging nail streak, a wide or very darkly pigmented streak, or a nail that is separating or lifting up from the nail bed should be examined by a dermatologist. A possible indication of advanced melanoma is if there is pigmentation in the nail fold skin or destruction of the nail plate associated with a nail streak. One study has reported that the tumors are most frequent on the weight-bearing areas of the sole, indicating that trauma is the important factor than sun exposure.The lentigo maligna melanoma arises on a sun damaged skin and accounts for 10 % of melanomas. Seen largely on meddle aged and elderly and occurs on the facial skin. Though it’s the most treatable variety it may be mistaken for an age or sun spot easily. It appears as a spreading brown flat patch with irregular borders. It spreads slowly, changes color and may feel lumpy as it grows

The nodular melanoma accounts for 15% of all cases and seen more in men, can appear anywhere and seen at an older age. When it appears it can grow rapidly in thickness and penetrate the entire depth than the skin breadth. Vigilance is essential as it may not arise from a preexisting mole. Often dark colored but sometimes may be colorless, may ulcerate or even bleed.

The commonest type which accounts for 70 % cases is superficial spreading type which can occur at any age appears largely on the skin between neck and pelvis has irregular margins and can reflect various shades of brown, gray, black, pink or white.

May start like a freckle but change color and grow over time. It can spread rapidly and also is the leading cause of death in most melanoma patients.

Non-pigmented Subtypes While uncommon, melanoma occasionally does not have brown or black pigmentation. An uncommon subtype called amelanotic melanoma usually appears as a pink or red nodule or lump.

Another uncommon subtype, desmoplastic neutrotrophic melanoma (DNM), usually looks like a non-pigmented scar. When a scar or keloid appears on the skin and the skin has not been injured, DNM is suspected. The lesion also can appear as a cyst that may or may not be pigmented. DNM tends to appear on sun-damaged skin in elderly patients, occurring mostly on the head and neck.

Following a comprehensive sun protection regimen goes a long way in stopping the development of skin cancer and delay skin aging; people of all ethnicities are encouraged to

• Seek the shade, especially between 10 A.M. and 4 P.M.
• Do not burn.
• Avoid tanning and UV tanning booths.
• Cover up with clothing, including a broad-brimmed hat and UV-blocking sunglasses.
• Keep newborns out of the sun. Sunscreens should be used on babies over the age of six months.
• Examine your skin from head-to-toe every month.
• See your physician every year for a professional skin exam

• Wear, broad spectrum Sunscreen, SPF >15, Water Resistant
• Use sunscreens daily. Even on cloudy , rainy days & while driving
• Apply liberally - Most people fail to achieve the SPF as listed on the bottle, because they apply too little sunscreen, thus purpose of the sunscreen fails to serve individuals at high risk, who may need a sunscreen with a higher SPF.
• Apply 30 mines before Sun Exposure
• Remember to apply over ears, bald head, back, neck, hands, back of feet
• Reapply every 2-3 hrs or immediately after swimming / strenuous activity/ or if sweating excessively
• Sunscreen should be applied indoor and at home too
• It should be applied as a good thick film and (0.5mm thick) and in enough quantity. A simple rule is 6 teaspoons for the whole body
  ½ tsf for face and neck
  ½ tsf for each arm
  1tsf for each leg and
  1 tsf each for chest and back.

Once detected the staging of melanoma is crucial in deciding the prognosis and line of treatment

Family history of dysplastic nevi
Complete cutaneous and mucous membrane examination
Dermoscopy
Skin biopsy
Lymph node biopsy
Body scans to detect spread

Treatment required may include
Surgical excision
Lymph nodes removal
Immunotherapy
Chemotherapy
Radiation therapy
And regular follow up

THE INFORMATION IN THIS ARTICLE REFLECTS THE VIEWS OF THE AUTHOR ONLY. A QUALIFIED HEALTH CARE PROFESSIONAL SHOULD BE CONSULTED BEFORE USING ANY THERAPEUTIC PRODUCT DISCUSSED. ALL READERS SHOULD VERIFY ALL INFORMATION AND DATA BEFORE TREATING PATIENTS OR UTILIZING ANY THERAPIES NOTED IN THIS PROGRAMME.