Lentigo Maligna: Causes, Symptoms & Treatment

Lentigo maligna is a diffuse, plane, and brown-black discoloration of the skin caused by atypical melanocytes. This phenomenon is caused by sun exposure and corresponds to a precursor of malignant melanoma. The affected area of skin is completely removed surgically.

What is lentigo maligna?

In lentigo maligna, clusters of atyptic melanocytes form in the epidermis. Melanocytes are the cells in the skin that produce and release pigment to the surrounding skin cells. Lentigo maligna is a degeneration process of the pigment-producing cells that occurs in the epidermis of the skin. Degenerated melanocytes are also known as melanomas. Since the melanocytes in lentigo maligna have not yet become actual cancer cells, but merely appear atypical, the disease may also be referred to as melanoma in situ. The peak age of this disease is around 50 years of age. Slightly more women develop the appearance. Many sources suggest the risk of degeneration of atypical cells is greater than 50 percent. Some even assume that atypical melanocytes regularly always develop into malignant melanoma. However, this development may take several decades.

Causes

As a precursor of melanoma, lentigo maligna is an in situ stage of black skin cancer. This disease has been associated primarily with UV radiation. However, since the disease has been found to occur more frequently in some families, scientists assume a genetic disposition as the basis. In this case, the genetic disposition refers primarily to skin color. Thus, well-pigmented people are disproportionately less affected by melanoma than people with a genetically determined light skin. This is due to the filtering effect of brown-black melanin. This dark type of melanin is one of two different types of pigment found in human skin. Each person’s skin color results from the genetically determined combination of light and dark pigment components. Pigmented people have more of the dark pigment. Studies have proven that this substance renders a high percentage of solar energy harmless.

Symptoms, complaints and signs

Lentigo maligna occurs preferentially on skin around the armpits, face, neck, and forearms or lower legs. Usually, the affected skin area is radiation damaged, so it has already been involved in a sunburn. Visible on these skin areas are brown to black pigmented and inhomogeneous discolorations of the epidermis. As a rule, these spots are only diffusely limited and not raised, but flat. Lentigo maligna can also affect the eye in rare cases. In this context, the phenomenon also appears on pigmented people, since the skin in their eyes is not pigmented. The discoloration is probably related to damage in the DNA of the melanocytes caused by sun exposure. In this way, a malignant cell clone of melanocytes can form in the epidermis. Lentigo maligna does not normally cause pain, itching or other discomfort.

Diagnosis and course of the disease

The first suspicion of lentigo maligna arises during the history and visual diagnosis. Histopathology is used to confirm the suspicion. Differentially, the physician must consider age spots in particular, but also a mature melanoma that spreads superficially. The prognosis for lentigo maligna promises almost 100 percent chances of cure. Even if a lentigo maligna melanoma has already developed, the prospects for cure are still good.

Complications

Treatment is usually necessary for lentigo maligna. Without it, the complaint can develop into skin cancer, which in the worst case can be fatal for the patient. Usually, this disease results in various brown regions on the skin. These regions must therefore be completely removed by surgical intervention. In many cases, those affected are ashamed of the symptoms and feel uncomfortable with the spots or suffer from reduced self-esteem. Furthermore, this disease can also occur in the patient’s eye, leading to various visual complaints and limitations in everyday life.It is not uncommon for those affected by lentigo maligna to suffer from pain on the skin or itching. These usually only intensify if the affected person scratches the respective area. This can also lead to bleeding and furthermore to scars on the skin. During the treatment itself, there are usually no complications. The affected areas are removed, after which the patient is still dependent on radiation. Furthermore, there is usually no reduction in the patient’s life expectancy.

When should one go to the doctor?

Signs of lentigo maligna should always be checked by a dermatologist. Because the skin lesions are a precursor to skin cancer, early diagnosis may save the patient’s life. Warning signs such as black discoloration on damaged skin areas therefore always require a comprehensive medical examination. If the skin areas suddenly change, this must also be clarified quickly. Bleeding or scarring should also be presented to a physician. Lentigo maligno occurs predominantly in people with a light skin color. Those who belong to this risk group must ensure adequate sun protection. Should a sunburn nevertheless occur, the affected skin area must be monitored by a physician. The dermatologist should be consulted if any of the skin changes mentioned above occur. Depending on the cause and severity of the symptoms, the physician may consult an internist. If psychological problems arise as a result of the skin changes, this must be discussed with a therapist or in the context of a self-help group.

Treatment and therapy

The affected area is usually completely removed in lentigo maligna. In this case, this procedure takes place within the framework of an excision. The affected skin tissue is surgically excised. Not only are the discolorations completely removed, but also the edges of the adjacent skin areas. Sometimes a safety margin is mentioned. The procedure takes place either under local or general anesthesia. As a rule, only limited areas of skin are affected by lentigo maligna. If wide areas of skin show discoloration, plastic coverage of the defects with full thickness skin may take place. If the lentigo maligna is located in an inaccessible position, laser therapeutic treatment may be preferred if necessary. Radiation therapy is not usually performed, as it is not yet actual cancer at this stage. X-ray irradiation can theoretically be performed, but it should be done with a maximum dose of 100 Gy and should only be used for areas that are difficult to reach. Patients appear for follow-up appointments after surgery to rule out recurrence of the skin lesions. Sometimes patients decide not to have the discolored areas removed. This procedure is not considered very advisable because of the high risk of degeneration of atypical melanocytes. Melanoma may take years or even decades to develop, but the sooner removal of atypical cells occurs, the safer. Hard-to-reach areas of skin, for example, are difficult to remove after degeneration to a lentigo-maligna melanoma, because neither laser treatments nor X-ray irradiation should take place at this stage.

Outlook and prognosis

If left untreated, lentigo maligna shows an unfavorable disease course. It comes in the further development to the formation of skin cancer. This results in a threat to the life of the affected person. If medical help is still not sought despite the increase in symptoms, the affected person dies due to the cancer. If the diagnosis is made at an early stage, an individual treatment plan is drawn up. This provides for the complete removal of the skin lesions. The procedure is associated with complications and side effects. Nevertheless, it is the only option that offers the prospect of freedom from symptoms. If the operation proceeds without further disturbances and incidents, the lentigo maligna is considered cured. Nevertheless, the patient must participate in regular control examinations in the long term, so that treatment measures can be taken immediately if the symptoms return. Due to the visual changes, secondary diseases may occur. There is a state of increased emotional stress.This can lead to the development of a mental disorder. When assessing the prognosis, it is important to consider the possibility of secondary diseases, which contribute significantly to a worsened outlook. The prognosis is also worsened in patients in whom the skin abnormalities occur in areas of the skin that are particularly difficult to access. Removal in these areas of the body is more complex and may not result in the removal of all diseased tissue.

Prevention

Lentigo maligna can be prevented by avoiding direct sun exposure, especially to sensitive skin areas.

Aftercare

As part of aftercare, it is important to keep the affected skin areas clean and avoid skin irritation from clothing or excessive touching whenever possible. In general, a healing ointment containing the active ingredient panthenol may be applied after consultation with the physician to speed skin rebuilding. Products containing cortisone should not be used, as they would cancel the desired inflammatory process necessary for the treatment of lentigo maligna. If the skin lesions are removed with the help of cryotherapy or surgically, small wounds are also left behind, which must be protected from contamination and kept dry until they heal. The most important aftercare measure is the lifelong sun protection of the endangered skin areas with the help of appropriate clothing and sunscreens. To protect the particularly sensitive skin of the head and face, affected individuals should always wear a sun hat or cap when in the sun. Regular self-examinations of the skin and biannual to annual checkups with a dermatologist ensure that newly appeared lentigo maligna can be treated at an early stage.

What you can do yourself

Individuals who have been diagnosed with lentigo maligna should undergo excision. Careful wound care should be taken after such a procedure, as there is an increased risk of infection and wound healing complications. If such complications develop, the physician must be informed. Otherwise, the lentigo maligna can form recurrences and possibly even cause cancer. In addition, those affected should pay careful attention to other, usually non-specific symptoms. For example, pain in the affected area indicates a malignant disease. After surgery, regular check-ups should be performed to ensure that the skin lesions do not recur. Patients who choose not to have the diseased area of skin removed should have regular cancer screenings, as there is a relatively high risk of degeneration. In some cases, the discolored areas can be treated by alternative remedies. Citrus acid, for example, has proven effective in lightening the skin when used regularly. Homeopathic remedies can also be tried in consultation with the doctor. As a rule, however, the physician will recommend conservative treatment, which can be supported by the affected person through sparing and strict hygiene in the affected areas.