Generality
Nodular melanoma is the most aggressive form of cutaneous melanoma.
In detail, nodular melanoma is a malignant tumor lesion that has a high mortality rate, probably because it is difficult to identify and characterized by a high speed of development. It is, in fact, a skin tumor that is manifested subtly and that could be confused with other benign skin lesions. Nodular melanoma, however, has characteristics and peculiarities that can be useful in the context of diagnosis.
Currently, the treatment involves the removal of the same nodular melanoma, which may be associated with pharmacological and non-pharmacological anticancer treatments (anticancer chemotherapy, radiotherapy, etc.).
What is that
What is Nodular Melanoma
Nodular melanoma is a malignant skin tumor . This is the most aggressive form of melanoma, since the tumor lesion tends to grow at high speed and develop in depth, giving rise to metastases. It is a malignant tumor that can occur at any age and in patients of any sex, although it tends to affect male patients over the age of 50 more frequently.
Although not too common, nodular melanoma has a moderate incidence. In fact, it is estimated that this malignant tumor represents about 10-15% of cutaneous melanomas that affect Caucasian patients. However, due to its aggressiveness and devious development, nodular melanoma has a high mortality in the first five years after its diagnosis. Not surprisingly, it is responsible for about 40-50% of deaths related to cutaneous melanomas.
Causes
What are the Causes and Risk Factors of Nodular Melanoma?
Like any other form of tumor, even nodular melanoma originates from an uncontrolled and excessive proliferation of cells, specifically, of melanocytes (the cells responsible for the production of melanin pigment). Following a series of genetic mutations, the melanocytes escape the normal mechanisms of cellular regulation, replicating themselves quickly and massively, completely or almost completely losing their function.
The reason why such mutations still occur is not entirely clear, but it is believed that the cause is multifactorial . In detail, among the possible factors able to favor or expose the patient more to the development of this type of malignant tumor, we recall:
- Genetic predisposition;
- Family history of nodular melanoma or other types of melanoma;
- immunosuppression;
- Presence of autoimmune diseases;
- Exposure to UV rays, clear phototype and presence of other types of melanocytic nevi, especially atypical or congenital giant (these are possible risk factors on which, however, there are conflicting opinions).
Did you know that ...
To be fair, unlike what happens with other types of melanoma, the relationship between nodular melanoma and UV exposure is not confirmed. In fact, nodular melanoma appears to occur mainly in people with poor skin photo-aging and may arise in sites that are generally not very exposed to UV rays. At the same time, it has been noted that this malignant tumor also occurs in people who do not have large amounts of melanocytic nevi. In fact, as will be seen later, in most cases, nodular melanoma does not derive from the malignant transformation of a melanocytic nevus, but it is a malignant lesion of recent formation.
Features
What are the characteristics of Nodular Melanoma?
Nodular melanoma appears as a cutaneous lesion generally detected compared to the rest of the skin, dome-shaped and with a usually hard consistency. The color is variable and can be black or dark blue, light brown, or it can take on the color of the skin or, possibly, a pink-reddish tone (in the latter case, we speak more properly of achromic or non-pigmented nodular melanoma ) .
Did you know that ...
When nodular melanoma occurs unpigmented it can be confused with a pimple or an acne lesion and therefore does not worry the patient. Unlike a common pimple, however, nodular melanoma does not tend to regress, but rather continues to remain on the skin and to increase its size. Moreover, sometimes the pinkish-reddish nodular melanoma has a dark pigmented edge (defined as "pigment escape"), a clear sign of the melanocytic origin of the lesion. These features should trigger the alarm bell in the same patient.
As mentioned, nodular melanoma can occur in areas where there were no lesions of any kind. Therefore, it is not said that - as happens on some occasions - the malignant tumor derives from a pre-existing melanocytic nevus that evolves towards a malignant form; but on the contrary, in many cases, it is a recently formed skin lesion.
However, among the areas most affected by the development of nodular melanoma, we find the head, neck, trunk, arms and legs. Of course, this does not mean that the tumor cannot manifest itself in other body areas.
Development of Nodular Melanoma
Another particular feature of nodular melanoma is the way it develops. This tumor, in fact, can manifest itself as a lesion of new formation that develops in depth from the first stages of growth. Unlike other forms of melanoma that tend to follow a radial growth (ie on the surface of the skin or "wildfire"), the nodular melanoma tends to develop little or nothing in a radial sense presenting, instead, a high growth vertical extension (that is, towards the deepest parts of the skin, until it reaches the subcutaneous tissue and the blood and lymphatic vessels, from which it can give rise to metastasis).
What characteristics should you pay attention to?
Given the subtle development and the sometimes "misleading" aspect, the identification of a nodular melanoma or in any case of a suspected lesion capable of pushing the patient to seek medical attention may be difficult. This becomes even more complicated if one thinks of the fact that nodular melanoma does not follow the so-called ABCDE rule as, instead, do the other forms of melanoma (for more information: Melanoma).
However, summarizing what has been said so far, we can affirm that the characteristics to pay attention to and that can make one suspect the presence of a nodular melanoma are:
- Domed shape with generally regular edges;
- Black or dark blue, brown or reddish-pink;
- Hard consistency;
- Very rapid development and growth;
- Tendency to remain on the skin and not to regress in a few days as it can happen, instead, for pimples and boils.
Symptoms
Manifestations and Symptoms of Nodular Melanoma
In the early stages of development, nodular melanoma appears as a cupoliform skin lesion - dark or non-pigmented, depending on the case - generally asymptomatic .
With the advancement of growth, however, the malignant lesion can give rise to a symptomatology considered typical and characterized by ulceration and bleeding . However, it should be pointed out that similar symptoms do not occur in all patients and that, in some cases, the lesion could remain asymptomatic.
Complications of Nodular Melanoma
The most worrying complication of nodular melanoma is metastasis . In fact, due to the high speed with which it expands and invades the skin tissues, the nodular melanoma is able to reach the underlying blood and lymphatic vessels favoring the entry into the blood or lymphatic circulation of the tumor cells that compose it even before be diagnosed.
Diagnosis
How do you diagnose Nodular Melanoma?
The diagnosis of nodular melanoma must be made by the dermatologist who, in addition to analyzing the suspected lesion by dermatoscope, can perform a biopsy in order to determine the malignant nature of the formation in question.
In case of suspected lesion, the dermatologist could advise immediate removal (without going through the biopsy) which results in a histological examination of the removed tissue.
At the same time, it is possible to perform a biopsy of the lymph nodes in order to assess the presence of a possible metastasis (sentinel lymph node technique; for more information: Melanoma - Diagnosis and Care).
Differential diagnosis
The differential diagnosis of nodular melanoma must be placed against other benign lesions - such as dermatofibroma, lesions from seborrheic keratitis or pyogenic granuloma - and against other malignant tumors, such as basal cell carcinoma.
Care and Treatment
How is Nodular Melanoma Treated?
Treatment and treatment of nodular melanoma depend substantially on the stage to which the tumor is located.
Undoubtedly, the first step consists in the surgical removal of the nodular melanoma, followed by its analysis. Depending on the size of the lesion removed and the depth reached, the doctor is able to establish the stage of the tumor and the consequent therapeutic strategy to be undertaken. If the thickness of the lesion is more than one millimeter, usually the biopsy of the lymph nodes is also performed. If the cancer cells are also spread to the lymph nodes, it is also possible to intervene surgically on them.
The other treatments that can be undertaken in the presence of nodular melanoma are anticancer chemotherapy (exploits the use of anticancer drugs) and radiotherapy (exploits the action of radiation beams or ionizing particles to eliminate malignant tumor cells).
Prognosis
What is the Prognosis of Nodular Melanoma?
The prognosis of nodular melanoma - due to its characteristics and subtle onset - is generally more severe than the other types of melanoma. If the tumor is diagnosed late, the prognosis may become worse.
In order to guarantee a greater probability of survival in the long term, therefore, the diagnosis should take place in an extremely early manner, indicatively, within the first two months after the appearance of the lesion. Therefore, in the event of the onset of lesions that may appear to be simple pimples, but which appear in unusual areas and which tend to grow with extreme speed, possibly giving rise to ulceration and bleeding, it is advisable to contact your dermatologist promptly, since that apparently harmless lesion could instead be the principle of a nodular melanoma.
Finally, we recall that - in the event that the diagnosis is made when the tumor has already given rise to metastasis - the prognosis of nodular melanoma, unfortunately, turns out to be poor in most cases.
