What is Melanoma Skin Cancer: Causes, Signs, Symptoms, Stages, Treatments

The epidermis is the uppermost layer of the skin. Among others, it contains cells known as melanocytes. These are the cells that make the skin look the way it does. Without them, people would have colorless skin.

Cancer is a disease that develops when cells start dividing rapidly and uncontrollably. This happens when a part of DNA is damaged or mutates. As more and more unnecessary cells are made, they accumulate to form a lump.

It is not uncommon for growths to develop on different parts of the skin and body. The main difference between growths said to be benign and cancerous ones is that the latter have the ability to migrate and invade other body parts. This is the reason as to why cancer is categorized among the most dangerous diseases. Cancers are mostly named according to organs or body parts they invade. Melanoma skin cancer is the type that develops on melanocytes.

What is melanoma cancer?

What is melanoma cancer and what does melanoma skin cancer look like? Simply enough, it is a cancer of the skin. There are other two types, of which melanoma is rarest but deadliest. It accounts for about 15% of all cancers of the skin. Early warning signs of this disease are often easy to detect during self-examinations. Since cells will still produce melanin even after invasion, melanomas are usually brown or red and sometimes pink. Other than these primary colors, melanomas have a tendency of developing multiple colors. There three main categories of this cancer:

Cutaneous melanoma

This type develops in cells found on outer skin layer, the epidermis. It consequently is the most common type. Most incidences are reported on skin regions often exposed to sun such as cheeks, legs and neck.

Mucosal melanoma 

It develops on epithelial tissues that secrete mucus or provides lining in body regions such as anus, gut, vagina and nose.

Ocular melanoma

This is melanoma of the eye. It usually develops in the uveal tract but can also begin in the conjunctiva. Ocular melanoma has a tendency to spread to liver.

Types of melanoma skin cancer

Melanoma is divided into 4 main types:

Superficial spreading melanoma (SSM)

This type accounts for most cases. In women, it often shows up on legs while the trunk and neck are its common areas of preference in men. SSM is slow growing and tends to spread across the affected skin area before metastasizing. Irregular moles are common warning signs.

Nodular melanoma (NM)

It accounts for most cases after SSM. The type gets its name from tendency to form red nodules. See nodular melanoma pictures. Once the nodules have formed, they rapidly penetrate the dermis and metastasize.

Acral lentiginous melanoma

Of all types, it is the rarest. Warning signs revolve around discolored spots or patches on palms or feet. A subtype of this melanoma affects nail matrix and nail plate. Melanoma on toe mostly develops on the big toe. On the finger, the thumb is often affected.

Lentigo maligna melanoma

This type is more common in older people. It is considered least invasive of all melanoma types. Early signs revolve around a mole with abnormal characteristics.

Signs and symptoms of melanoma cancer

Cutaneous melanoma

The ABCDE rule is often used to detect signs and symptoms of melanoma cancer when it occurs on the skin. The rule basically helps distinguish normal moles from malignant ones.

  • Asymmetry – normal moles should have two equal halves
  • Borders – irregular borders or edges are common signs of spreading malignancy on skin.
  • Color – normal colors for moles are brown and red. Malignant ones usually have multiple colors such as blue, green and orange. Some areas may also be highly pigmented than others.
  • Diameter – a skin lesion or growth larger than 3 mm in diameter should get checked. In fact, medical diagnosis is necessary for any growth that grows larger than it usually is.
  • Evolving – moles remain in the same status for long and sometimes eternally. Malignant tumors change in size, shape, color and sometimes texture.

Nodular melanoma

It is mostly characterized by a nodule that penetrates deep into skin but has a small tip above the skin. The nodule will in most cases be red in color. Nodular melanomas are often caught when they are 2 mm or thicker. This makes them the most dangerous of all melanoma tumors.

Acral lentiginous melanoma

Shows up in form of a longitudinal streak perpendicular to nail bed and running along the nail plate. The streak can easily be taken for a blemish or a blood blister. The cancer can start in the nail matrix, nail plate or the areas that surround the nail plate.

Mucosal melanoma

Bleeding is among common mucosal melanoma symptoms. For example, anal melanoma may cause blood in stool while throat melanoma may cause blood in the cough.

Ocular melanoma

Signs revolve around vision interferences. For example, patients may see shadows or light flashes. Melanomas in eye may also displace the pupil or cause blurred vision if on the retina.

Melanoma cancer causes

No one will tell you exactly what causes this disease. The only fact that can be explained is how the disease occurs and its risk factors.

Cancers, including melanoma, develop when DNA has some of its instructions manipulated. This means that some normal function of cells will be interrupted. In case of cancer, the interruption results in fast division and by-passed death of melanocytes. Factors that contribute to changes in DNA of melanocytes include:

  • UV radiation – UV rays contain a lot of energy. After a long time of constantly being exposed to them, mutation may occur.
  • Fair skin and blue eyes – people with fair skins have less melanin. This means that most of UV rays that reach the skin get absorbed into the skin. As hinted above, UV rays are potentially poisonous.
  • Sunburns – severe sunburns encourage melanomas in more than one way.
  • Dysplastic nevi syndrome – this is a benign condition that results in many irregular moles. Irregular moles show a tendency to develop into melanomas.
  • Compromised immunity – the body naturally identifies and stops abnormal cell functions. Diseases such as HIV that weaken the immune system may cause inefficiency in this natural defense mechanism.

Melanoma cancer stages

There are 4 main melanoma cancer stages. Sometimes, a fifth stage is included for precision. Results from scans and diagnosis tests determine the stage the tumors are in. The stages are:

  • Stage 0 – this describes in situ melanomas. At this stage, tumors are small and can be easily removed with excisional surgery.
  • Stage I – tumors are getting bigger but have not exceeded 2 mm in thickness. The tumors also have not left their initial positions.
  • Stage II – tumors have penetrated the dermis. This is the immediate layer of the skin after the epidermis.
  • Stage III – malignant cells have invaded the lymphatic system. There is possibility that local lymph nodes are swollen or will soon swell.
  • Stage IV – deadliest and last stage. Malignancy has spread to distant organs. The lungs and brain are often first organs to be invaded. In case of ocular melanoma, the liver is at a higher risk.

Centers such as Ocular Melanoma Foundation sometimes use a more advanced staging system, especially for ocular melanoma. The system is abbreviated as TNM. The T represents tumor and describes the size and thickness of melanoma. N is for nodes. It explains whether malignancy has reached lymph nodes. M is for metastasis. It explains the extent to which distant spread of malignancy has occurred.

Prognosis is always best for small melanoma tumors. Doctors use a tool known as 5-year survival rate to describe prognosis. At stage 0 and I, the rate is more than 90%. This drops drastically as the cancer advances. In fact, it is below 20% when the cancer has spread to distant organs.

Melanoma cancer diagnosis and treatment


  • Physical examination – a doctor will use the ABCDE rule to check for signs of malignancy. Patients will often be required to provide details on what symptoms they have been experiencing and when they started. Medical history details will also be helpful.
  • Biopsy – this is perhaps the most accurate method to tell if a growth on skin is cancerous or not. A small tissue is extracted and checked for cancer cells in the lab.
  • Imaging tests – examples include MRIs and CT scans. They produce images and pictures to show the location, size and whether tumors have spread.


There are several treatment options available. Most are also applicable when dealing with lung cancer, colon cancer, breast cancer and even blood cancer. They include:

  • Surgery – Excisional surgery is most common. A small excision is made and the tumor is cut out. Large tumors or ones in delicate areas sometimes require surgery to remove an entire tissue or organ. This treatment is not used in treating blood cancer. Imaging tests are required prior to surgery. This is especially for amelanotic melanoma treatment, where tumors are almost colorless.
  • Chemotherapy – this is one of the most common treatment options for cancer. Here, drugs are used to destroy cells with a habit of dividing rapidly. It happens that this is a main characteristic of cancer cells.
  • Radiotherapy – this uses powerful X-rays to kill malignant cells. Improvised equipment is used to focus the rays to avoid destroying even healthy cells. Radiotherapy requires several appointments and is rarely used alone for large tumors.
  • Immunotherapy – this treatment has recently been introduced. Drugs that boost the immune system are administered. They boost the ability of the body to fight cancer cells.
  • Targeted therapy – this is another recent treatment for melanoma. It makes use of drugs that specifically target certain functions of cancer cells. It addresses the downside of chemo to destroy healthy body cells.


Many experts believe that exposure to UV radiation plays a role in development of melanoma. Common sources of UV are the sun and artificial devices such as tanning beds. It is therefore suggested that preventing excess UV exposure may lower the risk of developing melanoma. This strategy may work for melanoma on head, neck, face and legs. It however has no effect for melanoma on the feet and palms.