Over 100 different diseases can collectively be termed as cancer. They are identified according to the part of the body they invade. Melanoma is the type that invades melanocytes. These are cells that make your skin, eyes and hair look the way they do. This skin cancer is said to be most dangerous of all tumors that grow on skin.
Melanomas are further subdivided for easier identification. When it develops under nails, it is known as subungual melanoma. This type is more common in dark-skinned individuals compared to other melanomas. This is attributed to the fact that the disease doesn’t appear to be caused by UV radiation exposure.
Treatment for small subungual melanomas is usually very effective. Survival rate is also high for small tumors. Complications arise when the cancer spreads to other parts of the body. This is very common since most people misdiagnose this cancer.
What is subungual melanoma (SM)?
The main difference between this subtype and other melanomas is the fact that it originates in nail units. The big toe and thumb are mostly affected by the cancer can develop in any other toe or finger. Variations of SM include;
- Subungual melanoma – it appears in the tissue protected by the nail. Signs of discoloration can be seen underneath the nail.
- Ungual melanoma – originates under the actual nail, the hard part of toe or finger made up of keratin. It is known as nail plate and is a modified form of epidermis.
- Periungual melanoma – it originates in the skin that surrounds the nail.
You are also likely to come across another form of melanoma that invades hands and feet. So what is acral lentiginous melanoma and how is related to SM? The only similarity perhaps is that both diseases originate in melanocytes and exclusive to limbs.
How fast does melanoma grow in the nails? It can take months or even years before the disease becomes invasive. This is unless a nodule has formed on the nail matrix. When that happens, you should see your doctor immediately. Melanomas that form nodules are very fast spreading. They can reach advanced stages in a matter of weeks.
Subungual melanoma symptoms
Subungual melanoma symptoms are at first often misdiagnosed as bruises or birthmarks. In fact, some people end up concealing them with cosmetics. One way you can identify early warning signs is by noticing a streak that extends from top of nail plate all the way straight into the cuticle. White melanoma will not exhibit these characteristics. This type is collectively known as amelanotic melanoma and tends to be colorless. Other common signs include;
- Black or brown longitudinal lines or streaks. They also may be blue or without pigment.
- Separation of nail from nail bed
- The skin surrounding the nail becoming dark or discolored
- Presence of a bruise with no link to a recent injury
- A small lump or nodule in nail matrix
- A bruise that takes forever to heal. Normally, bruised nails fall off and get replaced by new ones. Malignant ones will not heal on their own and in fact will spread.
- Cracked or distorted nail plate
These are signs of in situ or early melanoma. When it has already spread, metastatic melanoma symptoms that may occur include;
- Bloody cough, chest pain and difficulty breathing. These indicate tumor in lungs.
- Losing weight without trying to, vomiting, nausea and a lump in abdomen. They are signs of lump in liver or pancreas.
- Headaches, seizures and loss of sensitivity in limbs. These are signs of brain tumor.
- Blood in stool, abnormal bowel movements, nasal obstruction and nose bleeds. These are mucosal melanoma symptoms.
- Streaks that resemble the initial one in other finger or toenails. These are signs metastasized SM.
- Bone pain and frequent fractures. They are indications that tumors have developed in bones.
Subungual melanoma causes
It is known that melanomas are often caused by UV radiation exposure. In fact, direct sunlight is identified as one of choroidal melanoma causes. SM however appears to not be caused by sun. Some reports suggested that the cancer had something to do with injuries. However, most people with injuries do not always develop the disease and people diagnosed with the disease often report no recent cases of injuries. Regardless, occasional injuries and trauma such as fungal infections can encourage cells damage.
The one fact that everyone agrees on is that melanomas and other cancers develop due to cell mutation. This usually results from damaged DNA. Diseases and conditions such as HIV weaken the immune system and may make it easier for random mutations to occur. They therefore are categorized as risk factors.
Subungual melanoma subtype accounts for most melanoma cases in dark skinned individuals. More cases are also reported in people who are 50 years of age and above.
Subungual melanoma stages and prognosis
Subungual melanoma stages are based on how deep or widely malignant cells have spread. Prognosis is best for in situ tumors and worst once metastasis has reached distant organs. The following factors dictate prognosis reports;
- Stage – stage 0 tumors are most docile while stage IV ones are most invasive. 5 year survival rate in early stages is more than 90% but lower than 20% in advanced stages.
- Thickness – large melanomas require more than one treatment option to get rid of. Additionally, it is more likely to leave some traces of malignant tissues after removing a large tumor.
- Location – surgery is perhaps the main treatment option for tumors. When tumors are located in complicated areas, it is harder to have them removed with surgery or other treatments such as radiotherapy.
- Age – as we age, our bodies become less active and more susceptible to infections. This makes prognosis for most diseases poor in later ages.
- Health – the immune system normally identifies abnormal cells and destroys them. Poor healthy compromises the system in multiple ways, making prognosis likely poor.
The best option to better prognosis is having a doctor examine a suspicious streak, spot, line or bump on and near your nails. In this way, a subungual melanoma can be caught early before spreading.
In situ subungual melanoma complications include discoloration and cracking or distortion of nail. If a nodule forms, it may bleed and become infected. This increases chances of misdiagnosis.
More serious complications occur when tumors penetrate deeper into the skin and finally gain access to the blood or lymphatic system. From there, malignant cells migrate and invade other healthy organs such as the brain and lungs.
Subungual melanoma diagnosis
In a hospital, a doctor may perform the following tests to confirm diagnosis;
This involves checking for signs of subungual melanoma. It will be done with the help of a specialized lens which provides a magnified view of the nail. Details about your medical history and timeline of the symptoms will likely be required. SM is sometimes confused with;
- Onychomycosis – this is a fungal infection. It results in discolored (usually dark) lines which aren’t longitudinal.
- Hematoma – a hematoma is collection of blood outside blood vessels under the skin. It often results from injuries. Hematomas improve with time.
- Paronychia – this is an infection that occurs in the nail bed.
- Moles – moles are benign growths that appear on the skin. They usually are black or brown in color. Moles do not form streaks or lines.
Biopsy procedure is the most effective way to confirm diagnosis. A small tissue will be extracted from the nail matrix to be examined in the lab. Another form of biopsy may be conducted to check if malignant cells have spread to local lymph nodes. A special dye is injected in the site from where a tumor has been removed. It is then traced to nearby lymph nodes.
Tumors that have spread require imaging tests such as MRIs and CT scans. These will show the other organs that have been invaded. Imaging tests are also very essential when staging melanomas and deciding excisional margin.
Subungual melanoma treatment
There are several subungual melanoma treatment options available;
In earlier days, surgery involved amputating the entire affected finger. This has improved in recent days. Most SMs are nowadays removed locally and with very small excisional margins. If amputation is necessary, it will likely be done at the first joint.
Radiotherapy has been part of cancer treatment for long. It uses X-rays to destroy the malignant cells. The main disadvantage of radiotherapy is that it rarely removes all malignant cells. It is for this reason used in combination with other treatments or to reduce pain caused by spreading tumors.
Chemotherapy is somehow scary by name and also by results. It is the reason cancer survivors lose all their hair after treatment. The treatment uses drugs to kill cells that rapidly divide, as this is a main characteristic of cancer cells. The drugs can be injected directly or be administered systematically. Targeted therapy has recently being introduced as an advanced form of chemotherapy. It specifically targets cancer cells.
This is an emerging treatment option for malignant tumors. It boosts the immune system’s ability to fight malignant cells. The main disadvantage is that the treatment comes with many side effects. It however is very effective for tumors that have spread and when surgery hardly be used.
More advanced treatment options for melanoma and cancer in general are being tested and introduced. In fact, doctors use a combination of treatments to fully get rid of the disease. It is for this reason that patients are advised to seek medical attention in top centers such as Ocular Melanoma Foundation. Such centers do not just focus on physical treatment but also emotional support. This is a very important part of cancer treatment.
Prevention and outlook
It is yet to be known what causes melanoma exactly. Prevention revolves around measures to help catch the disease in its early stages. Such include performing self-examinations regularly and going for annual skin checkups. This is especially for patients under drugs that suppress immunity or diagnosed with chronic diseases. If you have ever been diagnosed with melanoma, ensure to go for follow-up appointments. Sometimes, some malignant tissues can be left accidently.
Subungual melanoma is not common but very deadly after metastasis. It starts in nail matrix and often mistaken for bruises and other types of nail blemishes. While common blemishes will tend to improve with time, malignant ones spread and persist unless treated.
There are many images, photos and subungual melanoma pictures online which can help identify the warning signs of the disease. While a doctor is the only one who can correctly diagnose the same, you have the responsibility of reporting malicious streaks on your finger or toenails.