Subungual melanoma: how it looks, treatment

Cancer diseases - one of the greatest problems of mankind, which every year becomes more urgent. A tumor can appear anywhere in the human body and spread to large areas through metastasis. Skin cancer (and it also has several types) is one of the most common pathologies in cancer practice. But the championship on lethality in the first year of the disease still holds one of the types of skin cancer - melanoma. True, under melanoma is often implied a tumor of melanocytes on the surface of open areas of the skin, and not everyone suspects that such a neoplasm is possible in the nail area. Dark spots under the fingernail are often written off for trauma with a hemorrhage (bruise, hematoma), but in fact it can be a malignant entity - subungual melanoma.

[1], [2], [3]

Epidemiology

Since cell degeneration occurs when they are damaged, the risk of developing a nail melanoma is relatively low. Still, the cells of the nail bed are protected from damage by a dense nail plate. According to statistics, only 0.7-4% of tumor processes on the skin are diagnosed in the nail area.

The risk of developing subungual melanoma on the arms or legs is approximately the same, which can not be said about the different fingers of the limbs. The thumb is most susceptible to injury (especially on the legs), so the melanoma of this finger is most common. By the way, in 4 out of 10 cases of nail melanoma patients indicate his trauma in the recent past.

Most often the disease affects adults. After 55-60 years, this indicator is maximal. Podnogte melanoma in children is unlikely. Usually a dark spot in the nail's area of the child turns out to be a nevus that causes the appearance of a characteristic band (melanonichia) on its surface.

The most predisposed to the development of the subungual type of melanoma are people with dark skin color (blacks, Indians, Hispanics, Asians).

In representatives of the black race, the disease develops mainly against the background of melanonichia (melanin deposition in the nail plate). Black people of the planet have a tendency to form dark spots on the nail bed and in the nail plate, but often pathology is not considered an independent disease, considering it a symptom of other diseases, among which is the subungual melanoma.

[4], [5], [6], [7], [8], [9], [10], [11], [12]

Causes of the melanoma of the nail

We have identified several factors that can lead to the degeneration of cells in a specific area of the skin: trauma, UV radiation, pigment nevi, hereditary predisposition. Now we will try to consider the causes of melanoma under the nail more enlarged.

To begin with, when we talk about nevi, we suspect mostly moles or birthmarks. In fact, hemangiomas (not a malignant vascular tumor that usually appears immediately after the birth of a child), papilloma (benign tumor caused by papillomavirus), warts (viral neoplasms on the body) also have similar properties . Despite the fact that all such growths are benign, their damage is likely to lead to a change in the properties of cells and malignancy of the process.

In principle, the cells of any build-up on the skin of the finger, which existed for many years, without bringing much anxiety to the owner, are the main blow to themselves when traumatized, therefore they are damaged more than others. At the same time, the risk of developing malignant processes is higher in this case, and it does not matter where the outgrowth was formed: on the exposed skin or under the nail plate.

At the age of 40 years, some people on the skin appear some formless dark spots, reminiscent of birthmarks. At the age of over 50 years, such marks appear already in many and not one by one. This pathology is called seborrhoeic keratosis ( senile keratoma ), and it is caused by a violation of keratinocyte production in the basal layer of the skin. The neoplasm itself has a benign character. But over time, it begins to rise higher above the skin and becomes more prone to injury. If such a stain appears on the toes, it can be squashed or rubbed with shoes, suffering during strokes, etc., which can lead to the degeneration of cells. And there are quite a few such cases.

[13]

Risk factors

Risk factors for the development of subungual melanoma are any previously diagnosed types of skin cancer and connective tissue, as well as a hereditary predisposition to oncological diseases. Even if a cancerous tumor has a localization within the body, it can give metastases to the nail roller, the nail base, etc.

When we talked about black people, we noticed that the predisposition to subungual melanoma is associated with more frequent cases of melanichia development. The incidence of this disease in the Caucasoid race is less than 1%. But this does not exclude the appearance of a subungual type of melanoma in people with fair skin. Regardless of the location of the focus of melanoma, people with fair skin are more likely (they usually have light or red hair and blue eyes), a large number of birthmarks, and freckles on their face.

It is clear that the risk of malignant cell degeneration is higher in people who like to take sun baths, especially during hours of increased sun activity, sunbathing in a solarium, working in the open air. As for solar radiation, it is not uncommon for skin burns, obtained in tender childhood, to become an oncological problem in an adult person, sometimes several decades later.

Fingers are parts of the limbs, the traumatizing of which happens very often. But even if the finger and nail injuries are not a rare occurrence even in domestic conditions, then what about production conditions, where the bulk of the work is done by hands, or doing sports with a high risk of toe injuries (eg, football) and melanoma development of the big toe , in fact this finger suffers more often and more than others.

It is clear that without provoking factors, no growth on the fingers or under the nail plate will turn into a malignant tumor. But how to avoid these provoking factors, if our living conditions, nutrition, work already present a risk of injury, poisoning of the body with carcinogenic substances, irradiation with solar UV light. It turns out that the risk of developing subungual melanoma is quite large for each of us living in modern conditions, working in the production and forgetting the taste of natural products. The villagers just win this.

[14], [15], [16]

Pathogenesis

Under melanoma is commonly understood as a tumor that develops from human pigment cells (melanocytes). For this reason, in most cases, it is not difficult to diagnose it, because the tumor has a darker shade than the rest of the skin. True, a fifth of melanoma can be considered an atypical cancer (pigmentless melanoma), because the tumor does not have a characteristic dark shade due to a small number of melanocytes or their absence.

Most often, melanoma affects open areas of the skin. On the mucous membranes, the retina of the eye, under the fingernails it can be detected much less often. And this is understandable, because any cancer does not arise from scratch. And the main provoking factor that causes the degeneration of cells is their traumatization, and the exposed skin is the most exposed to it.

Under the injury of the cell does not necessarily have to suspect a stroke. With the same probability, it can be a "burn" due to exposure to sunlight or chemicals.

Any factor that causes cell damage can lead to necrotic changes in it, followed by proliferation and restorative processes. But everything would be fine, if not for the influence of carcinogenic factors, which every year becomes more and more. So studies conducted in 1979-2004, showed that over 15 years the number of proven carcinogenic factors increased more than 4 times, and factors with probable carcinogenicity - more than 10 times. It is not difficult to guess that in the next 13 years these figures have increased, as well as the percentage of the incidence of skin cancer.

It is not necessary to think that carcinogens are something abstract. They surround us everywhere. But the most dangerous are those that enter the body with food (and the number of products containing carcinogens, all the time growing as the industry develops), while smoking cigarettes or inhaling harmful substances when doing work at chemical, metallurgical , woodworking and some other types of industry.

The most dangerous they are considered because their effect on the body daily and very much. Someone has to work in harmful enterprises, we have limited choice of products that are clean from carcinogens, and people try to stop smoking various experiences, including those related to work and nutrition. Alcohol, infections, adverse environmental conditions, drugs have long ago come to the fore, although their influence should not be ruled out.

What happens under the influence of carcinogens? Damage to the cell can occur with changes in DNA, as a result of which the protein structure and cell functions are disrupted, they degenerate and can become malignant. Carcinogens can delay the proliferation of cells, i.e. Cells continue to divide even when there is no longer any need. The process of proliferation out of control of our body, the tumor continues to grow and spread throughout the body.

At the same time, cancer cells are incredibly tenacious. Not only are they multiplying uncontrolledly, they squeeze organs and tissues, disrupting their work, so in addition they begin to release toxic substances that are detrimental to healthy cells, including cells of the immune system, poison the body and drain its forces. By metastasizing, they spread throughout the body and create new tumor sites, disabling vital organs.

With regard to ultraviolet radiation, because of which it is considered dangerous to prolonged exposure to the sun, sunburn in a solarium, etc., it can also change the differentiation of cells under the influence of free radicals.

Do not think that the trauma of the cells must necessarily cause cancer. It causes the onset of the proliferative process. But it is at the moment of division that cells are considered to be particularly sensitive to negative effects. The more carcinogens enter the body, the greater the risk of disrupting cell differentiation, changes in their DNA, excessive reproduction, uncontrollable to the body.

There is a certain percentage of people with a hereditary predisposition to cancer. They have changes in the DNA of cells genetically. And yet, without the influence of provoking factors, the risk of developing melanoma remains low.

Most of the melanoma of the skin, including subungual melanoma, is associated with pigment nevi, which also do not pose a hazard until they are affected by damaging factors: injuries and UV radiation. Melanocytes are particularly sensitive cells, so their damage causes not only active proliferation, but also quite frequent malignancy (cell degeneration).

[17], [18], [19], [20], [21], [22]

Symptoms of the melanoma of the nail

Podnegte melanoma is a disease similar in its symptoms to some other diseases: nail fungus, hematoma after trauma, subungual nevus, melanonichia, wart under the fingernail, paranichia or panaricium (inflammation or pus formation in the nail and nail base). This makes it difficult to diagnose pathology.

And yet, what should alert a person? What signs can indicate that the appearance of a dark spot and inflammation in the nail area is not the simple consequences of trauma, but the beginning of a malignant process? Consider the symptoms characteristic of the onset of the disease:

1. The first sign of a possible pathology is a change in the color of the nail and tissues under it or around the nail plate. This does not necessarily have to be the entire nail, most often the pomemance is observed on some part of the nail, for example, at its base. Fabrics in this case can be painted in burgundy, rich, red, brown, violet-black and even blue.

It is clear that the darkening of the tissues in the nail area is possible due to severe trauma with hemorrhages (bruise). But usually the symptoms of the trauma take place within 10-12 days. If this does not happen, it is worth consulting with a doctor and diagnosing the site of damage.

Naturally, if a dark spot was formed not due to trauma, it should be examined.

1. If it is a non-pigment melanoma, then the darkening of the tissue may not be observed. Yes, and pain in the early stages of the disease there. For this reason, the pigment-free form of the disease is usually diagnosed with a delay, when its treatment is already very difficult and rarely yields good results.

But both the pigmented and non-pigment melanoma grows little by little and a longitudinal strip appears above the nail plate above it. Most often this strip, which has a darker color than the rest of the tissue, is located strictly in the middle of the nail, but it happens that it is shifted to the right or left of the center of the nail platinum. An identical situation is observed with melanonichia.

Over time, the band becomes darker and expands. This is different from the strip on the nail plate caused by a hemorrhage due to a microtrauma or taking some medications, which in time does not change in size and shifts as the nail grows. In dark-skinned race, the appearance of a dark band is a peculiar feature, and does not always indicate a melanoma.

The melanoma band expands until it covers the entire surface of the nail. Sometimes the process is thrown on the lateral (side) nail rollers, which also change the skin color to a darker one.

1. First, the tumor is not probed and can be suspected only by changing the color of the nail tissue, but as it grows, it becomes denser and begins to press on the nail plate, causing its destruction. The nail is frayed, it becomes brittle, cracks appear on it. Coupling with the nail bed is reduced. All these signs are very similar to the nail fungus.

As the disease progresses from the nail bed, succulence and pus appear. The tissues around the nail are inflamed, abscesses form between the nail plate and the lateral nail ridges. From the side it looks like an ordinary inflammation of the peri-osedocular roller (paronychia). When there are suppurations in this area, you can suspect panaric attacks. But in fact, everything can be much more dangerous, because the appearance of pus from under the nail and in the surrounding tissue is one of the symptoms of subungual melanoma.

Next on the site of abscesses are formed sores, which gradually become larger in size. Attempts to treat the disease with anti-inflammatory and antibacterial ointments do not work, because it's not about the infectious process. Sores can fester or ooze, they are rather painful, but do not heal, no matter what measures are taken.

If at first the melanoma resembles a small tubercle, then in due course it changes its shape to a mushroom shape with a fleshy "hat" and a thinner leg. This is a characteristic sign of melanoma, although again it can be seen that it is similar to the papilloma.

It must be understood that the malignant process has the property to spread not only over the surface of the skin, but also inside the tissues. If at the first stage the pain with pressing on the nail is almost not felt, then with the spread of the tumor process to other sites and deep into the bone, the pressure on the finger will be accompanied by severe pain. When pus appears under the fingernail, the pain can be of a constant pulsating nature.

It is clear that inflammation with the formation of pus and dystrophic processes in the nail disrupt the nourishment of the nail plate, as a result of which it separates from the nail bed, which is actively progressing malignant process. But now he is no longer hidden from the eyes, and there is no doubt about his character. True treatment for this stage of the disease has no longer such encouraging results.

Stages

Symptoms of melanoma may vary somewhat depending on the type of pathology and its stage. There is no strict classification according to the types of nail melanoma, but distinguish:

• melanoma, which develops in the area of the matrix (base) of the nail, then immediately there is a darkening of the nail in the region of the lunula,
• melanoma, which originates under the nail plate (in this case, a dark spot can appear anywhere on the nail and, as the nail grows, extend into a colored strip)
• melanoma skin near the nail plate (the spot appears on the periphery of the nail, but gradually spreads further).

It should be understood that all these signs are applicable to pigmentary melanoma. When pigmentless form, external manifestations are not observed until the appearance of brittle nails, pus and sores. Also, over time, you can feel the seal under your fingernail.

With regard to the progression of the disease, the initial stage of subungual melanoma resembles the subungual hematoma with the appearance of a dark spot on the nail, which gradually lengthens and grows with the nail. Other signs are usually not observed.

At the second stage of the disease, the nail is destroyed, there is a purulent inflammation. By the end of the second stage, there are multiple ulcers under the nail plate and next to it, with which the oozing oozes. Further, the nail is detached.

About the third and fourth stage of subungual melanoma it is known that during this period there is a process of metastasis. First, inflammation of the regional lymph nodes and their densification due to the proliferation of malignant cells and individual foci of the tumor process in nearby tissues, subsequently appear distant metastases, affecting the internal organs of man.

Depending on how the malignant cells spread: with lymphatic flow or through blood (lymphogenous and hematogenous way of metastasis), the disease will proceed slowly (in the first case) or aggressively, in a short time hitting large areas of the body (when spreading with blood flow on the blood vessels).

[23], [24]

Complications and consequences

Cancer is a terrible new growth, regardless of where it is found. After all, cancer cells not only multiply excessively, forming seals, compressing nearby organs and violating their functionality. They also poison the body and destroy healthy cells. Through their fault, the body experiences various disruptions, and when it comes to vital organs, the patient's death sets in.

Usually a lethal outcome is associated with a large tumor size or metastases in the heart, kidneys, lungs. While the tumor is small and has not metastasized, it can be safely removed, but again everything depends on the prevalence of the process. Sometimes surgeons are limited only to the removal of the nail or distal phalanx of the finger, in other cases it is necessary to remove the entire finger. If the process of metastasis has not been started, one can hope for a favorable outcome of treatment, otherwise malignant foci may appear later in different parts of the body.

In the case of the spread of malignant cells through the blood, the disease develops very quickly, and by the time of its diagnosis it can go to the third or fourth stage. First, a person suspects a nail injury with the formation of a hematoma, then he begins to treat the destruction of the nail and abscesses, considering them the intrigues of fungi and bacteria, and when the treatment does not work, he comes to a doctor who diagnoses a neglected stage of the disease, first symptoms.

The situation is not the best with the non-pigmentary subungual melanoma. First, she does not show herself in any way, then a light wart that raises her nail appears. Over time, the wart acquires a specific mushroom shape, and it would be time to think about what it could be. But while she does not hurt, very few people start to worry about her appearance. When pain occurs, it turns out that the process has gone deep inside and affects the bones.

[25]

Diagnostics of the melanoma of the nail

If you carefully study the symptoms of subungual melanoma, you can see that there are actually no specific symptoms by which the disease could be diagnosed with great accuracy. Neoplasm at different stages of development will resemble the clinical picture of many other diseases, which significantly complicates the diagnosis. And often just delays the moment of treatment to the doctor and becomes the reason for belated treatment without any guarantees.

By appearance of pigmented melanoma, a doctor can only suspect an oncology. To confirm the diagnosis, you will also need to assign a clinical blood test and a blood test for oncomarkers. But again, a positive result speaks only of the presence of a malignant process in the body and does not provide information about its localization. Perhaps the patient has a normal hematoma on the nail, which is mistakenly removed, but this will not relieve him of the tumor in another place, which no one even suspected.

Confirm that the dark spot on the nail and there is melanoma can be using instrumental diagnostics. At the forefront, of course, is dermatoscopy, i.e. Inspection of the spot under the fingernail with a special device - dermatoscope. This modified microscope allows to scan through even the stratum corneum of the nail plate to detect underneath the malignant cells or to exclude the diagnosis of cancer.

Digital dermatoscopy allows you to obtain an enlarged image of damaged tissues on the computer monitor and make a high-quality picture for further study and consultation.

It is clear that at an early stage, when malignant cells are still small, dermatoscopy can not reveal them, especially if the study is conducted by a doctor with insufficient experience. The only way to fully confirm or disprove the diagnosis of subungual melanoma is a biopsy, during which a sample of tissues from under the nail is taken to a depth of 3 mm.

To get an informative sample in the field of a dark spot at the base of the nail, you need to puncture or remove the nail plate. But it is best to remove not only the nail, but a suspicious lesion with adjacent to it areas of healthy skin. The point is that a biopsy, i.e. Disruption of the tumor tissue, can provoke an even greater proliferation of cells and tumor growth, which in addition in a short time can give metastasis. In order not to risk a biopsy it is necessary to take from a remote site of the nail, where the nail plate enters, muscle tissue under it, subcutaneous fatty tissue, and sometimes the entire distal phalanx of the finger, if the process was widespread.

Experiencing a remote nail and a wound in the nail bed is not necessary. The wound will drag on, perhaps even soon grow a new nail. But it is better to remove the hematoma than to ignore the cancer tumor or to disturb it and cause metastasis. At the early stage of the disease the probability of a complete cure is quite large.

If the biopsy confirms the diagnosis, it is important to understand at what stage the disease was detected and whether the tumor has metastasized. To detect metastases, they resort again to instrumental diagnostic methods: ultrasound examination, radiography, computer and magnetic resonance imaging. If there is an increase in regional lymph nodes, a puncture biopsy is necessary to determine whether the change in lymphatic vessel size is associated with the proliferation of malignant cells within them.

[26], [27], [28]

Differential diagnosis

Qualitatively conducted differential diagnostics of dark spots on the nail often allows to avoid unjustified removal of tissues. Subungual melanoma can be confused with melanonichia, subungual hematoma,  fungal infection, panaritium, purulent granuloma due to the similarity of external signs and the nature of the lesion. Podnevtvaya wart can cause suspicion of unpigmented melanoma, and podnogtevaya hematoma - on the pigmented.

In order to differentiate diseases and exclude the wrong diagnosis it is very important from the patient's words to study the behavior of the spot or the tubercle in the nail area. With melanoma, they will necessarily increase in size. Pay attention to the nature of pain. The appearance of a dark spot that is not associated with trauma and does not cause painful sensations when pressing, is likely to indicate a malignant nature of it.

Treatment of the melanoma of the nail

As we have already said, cancer cells have high survivability, so chemotherapy or irradiation without removing the tumor can hardly guarantee the complete destruction of malignant particles. In addition, to accurately diagnose cancer by biopsy results it is still more expedient and safer to first remove the tumor. So it turns out that surgical removal of subungual melanoma is the main method of its treatment.

If the tumor is relatively small and does not go deep inwards, the phalanx is sanitized with the removal of the nail plate and soft tissues beneath it to the depth of tumor penetration plus some of the healthy tissue is captured. If the process has spread to the peri-oral grooves, even a part of the finger bundle is removed, but the phalanx is retained.

In the case of deep penetration of the tumor and metastasis into bone tissues, sanation, as a method of  surgical treatment, no longer makes sense and one has to resort to amputation of the distal phalanx (most often the finger). Thus, it is possible to prevent the spread of cancer cells by hematogenesis.

If the enlarged lymph nodes are detected after the biopsy and the presence of cancer cells in them is prescribed, lymphadenectomy, i.e. Excision of an oncology-affected lymph node. All this is done in order to block the lymphogenous way of spreading cancer.

Other methods of treatment for nail melanoma are prescribed only after removal of the tumor. It is a question of chemotherapy (drug treatment with potent agents), radiation treatment, which is a dosed irradiation of a specific part of the body in the region of the finger (if the tumor has metastasized, irradiate other areas of the body), immunomodulating vaccines and sera containing antibodies. Effective immunotherapy with melanoma.

With regard to chemotherapy, the treatment can be carried out by two types of drugs - cytotoxic drugs and cytotoxic drugs. The first inhibit the multiplication of cells and lead to their decay (death) due to the inability to divide, the latter - lead to the intoxication of cancer cells as a result of which they perish.

After removal of the tumor without metastases, local treatment with chemotherapy can be administered (ointment applications, rinsing of the wound with solutions, administration of drugs directly into the tissue of the affected finger). If the metastases do not go beyond the finger, regional chemotherapy is performed, i.e. Drugs are injected directly into the diseased organ. When spreading metastases beyond the finger and spreading them to the internal organs requires systemic chemotherapy (drugs are administered intravenously or orally).

Usually, even such a complex and difficultly tolerated treatment gives good results only in the early stages of the disease. Further, it only slightly prolongs the life of patients and requires additional administration of anesthetic drugs, since the spread of the malignant process inside is always accompanied by severe pain.

Prevention

Oncologists believe that you need to pay close attention to any changes in the nail after the injury. Such changes should be considered malignant until the opposite is proven. Maybe someone will find this strange, but this attitude to the problem is justified. It is better to be safe than to die because of a neglected bruise, which at some point has turned into a cancer tumor.

It would be better, of course, to avoid injuries to the limbs and limit contact with the sun's rays, using protective equipment and observing some caution. But this is not always possible. For example, not everyone will give up a sports career only because a finger injury under the appropriate conditions can lead to the formation of subungual melanoma. It is not always possible to avoid domestic injuries or damage to the nail in the workplace, because other people can become the cause of accidents, no matter how a person is not protected.

Forecast

When talking about the treatment of cancer, it rarely comes about long-term predictions, it's not always possible to get rid of cancer cells, besides, the illness severely depletes the body and makes it more susceptible to other diseases, for example, diseases of the infectious plan against which the forces already does not remain. Weaken the body not only the disease, but also the ongoing chemotherapeutic treatment or radiation therapy. Sometimes the tumor forms again, but in another place.

Usually, making any predictions, speak of a five-year survival threshold. It is believed that if the patient has not died during this time, i.e. The disease has not returned, there is a chance of a full recovery.

So, at the initial stage of subungual melanoma, the five-year survival rate is 75-88%, which is considered a high index. The forecast for the second stage is much worse - about 60-70%. In the third stage, when metastases spread only to the lymph nodes, we can speak only about 40%, and then the risk of relapse after 5 years after surgery with a sluggish flow of the process is great. When the internal organs are damaged (stage 4), up to 85% of patients die within five years, and only a few transgress this threshold.

It turns out that the earlier a patient turns to for help, the more he has the chance of a full recovery in the appointment of adequate therapy. This suggests that you need to pay attention to any changes in the color or shape of the nail, the appearance of new nevuses and seals on the fingers, the formation of longitudinal lines on the nail and their behavior. If there is a discoloration of the subungual nevus, widening of the band on the nail and thickening of the nail plate, it is necessary to consult with the doctor.

The only thing that remains for us is to closely monitor our health, to be as accurate and cautious as possible, to regularly inspect our body for the presence of incomprehensible growths, tubercles, pigment spots, pay attention to the discoloration of the color and shape of the moles, the appearance of dark inclusions on them, jazvochek, cracks, changing the shape and thickness of the nail. Only in this case there is a great chance to avoid such a deadly disease as a subungual melanoma. Do not think that if the pathology is rare, then it will not affect us. This attitude to the problem is fraught with great disappointment.

[29], [30]