Dermoscopy of Lentigo Maligna

Lentigo maligna is a form of potentially serious skin cancer, and it is a early stage of lentigo maligna melanoma. Malignant cells of lentigo maligna usually occur in the epidermal layer of the skin. When its malignant cells invade into the dermis or deeper of the skin, then lentigo maligna transforms into lentigo malignant melanoma. Therefore, it is particularly important to detect lentigo maligna at its early stage. Dermoscopy is an examination tool that plays an essential role in the diagnosis of early lentigo maligna.

What is advanced lentigo maligna?
Advanced lentigo maligna refers to an advanced stage of lentigo maligna. Lentigo maligna is a early stage of lentigo maligna melanoma. Malignant cells of lentigo maligna usually occur in the epidermal layer of the skin. But advanced lentigo maligna means its malignant cells already have grown from epidermal layer into the dermis or deeper of the skin, it transforms into lentigo malignant melanoma. So advanced lentigo maligna also called as lentigo maligna melanoma.

Clinical features of advanced lentigo maligna (lentigo maligna melanoma)
Advanced lentigo meligna usually appears as a large size, irregularly shaped patch of dark skin, varying shades of brown, especially black or blue. It have over thickness of the lesion part, sometimes it may bleed or ulcerate. When it is touched, it shows itching or stinging.It generally develop on sun exposed areas, such as face, neck, nose and arms of middle-age and elder persons, and slightly common on female.

Causes of advanced lentigo maligna (lentigo maligna melanoma)
Sun exposure is a significant high risk factors of advanced lentigo maligna, besides, there are other typical factors cause the diseases of advanced lentigo maligna, like below: Age: As the growing of age, more accumulated sun damage increase the risk of lentigo maligna. That is the reason why lentigo maligna usually happens on middle-age and elder persons. Skin Type: Fair skin people are more likely to have lentigo malgna than dark skin people.
Previous Skin Damage: Previous skin damage will increase the risk of lentigo maligna.
Weakened immune system: People with weakened immune systems have a higher risk of lentigo maligna.

High risk group
Usually, lentigo maligna occurs in middle-age and elder persons more frequently. And the prevalence rate of lentigo maliga of female is slightly higher than male.

Dermatoscopic features of advanced lentigo maligna
As advanced lentigo maligna usually appear as a large, irregularly shaped patch of dark skin in varying shades of brown, black, or blue. Its appearances are similar to other skin lesion, such as seborrheic keratosis, actinic keratosis, etc. Hence it is very difficult to recognize advanced lentigo maligna. At this situation, dermoscopy plays a really crucial roles in the detection and diagnosis of advanced lentigo maligna.

What is Dermoscopy?
Dermoscopy, also know as dermatoscope, is a handheld aiding device used by dermatologist to observe and diagnose skin lesion and skin diseases, like advanced lentigo maligna. Dermoscopy allows a enhanced visualization field of structures and patters of skin in details by uniting magnifying lenses and powerful lighting system. By using of dermoscopy, dermatologists can make a more accurate and precise analysis and diagnosis of skin lesions.

Dermatoscopic features of lentigo maligna melanoma
There are some certain characteristics of dermoscopy of lentigo maligna melanoma included:
Pseudonetwork on the face: Pigmentation appears around prominent facial hair follicles. Pigmented pseudonetwork is the main features of facial lentigo maligna of dermoscopy.
Asymmetrical pigmented hair follicle openings
Dark rhomboid structure: Proliferation of melanocytes around hair follicle space
Gray spots/lumps/balls: This is the only diagnostic feature in some cases of malignant lentigo) 
Dark streaks: lines of melanoma cells in the epidermis or superficial dermis)
Zigzag shape: A series of brown or blue-grey dots forming a zigzag shape.
Others: Color change, irregular and blurry structure and structureless areas are also the main dermoscopic features of lentigo maligna.

Identification of lentigo maligna melanoma by dermoscopy
Senile plaques are typically brown patches and occur on sun exposure areas with multi colors in numbers. But comparison of lentigo maligna, senile plaques are flat, well-defined, and it will not change its size or colors over time. Hence, the dermoscopy takes the role as a monitor to inspect the spots if there is a change or abnormal appearances to identify lentigo maligna from senile plaques.

Due to the looks of lentigo maligna, it brings difficult to distinguish lentigo maglina from other pigmented lesions , such as pigmented actinic(solar) keratosis, seborrheic keratosis, benign lichenoid keratosis by simple naked eye examination. If lentigo maligna is inaccurately diagnosed as a benign skin lesions, like actinic (solar) keratosis which is harmless. It may delay the treatment of lentigo maligna. And let lentigo maligna grow into lentigo maglina melanoma finally. The most useful and noninvasive diagnosis method of lentigo melanoma is to use dermoscopy combining with clinical experience.

The role of dermoscopy in the diagnosis of advanced lentigo maglina (lentigo maligna melanoma)
It is no doubt that a dermoscopy plays a significant role in the detection and diagnosis of lentigo maglina. The key roles lie in such aspects like:
Help skin doctors to make accurate analysis and diagnosis: Under dermoscopy, it allows a enhanced and brightened visual field even some hard-to-reach areas that are invisible by naked eye.
Evaluate the severity of lentigo maglina: Dermoscopy can identify which stage lentigo maglina is in, early stage or advanced stage, then aid skin doctors to evaluate the severity of it.
Monitor the process of lentigo maglina: Dermoscopy is a great help to monitor the growth of lentigo maglina by releasing more clear details of it.
Judge the treatment effect: Dermoscopy can give timely feedback of the treatment effect of lantigo maglina. So that skin doctor can decide if treatment methods need to be adjusted or not.

Precautions for public use of dermoscopy
Dermoscopy is a reliable and helpful technique that helps person to detect and diagnose skin lesions or skin diseases. In professional hands, it is easy to identify a vary of skin diseases. Meanwhile, it is important to use dermoscopy correctly to maximize its effect. There are soem precautions for the use of dermoscopy, the same as the public use of dermoscopy.
Correct operation method of using dermoscopy
How to identify suspicious lesions under a dermoscopy
The need for prompt medical treatment if any atypical lesions are found
Cooperate with doctors for diagnosis and treatment in time

Even though lentigo maglina is a slow-growing cancer. It meas that there is a long way to go from lentigo maglima to lentigo maglima melanoma. But the risk of invasive melanoma is greater when the diameter of lentigo maglina is over 4cm. If left untreated, lentigo maglina may evolve into lentigo maglina melanoma that grows and spreads quickly to other parts of skin. Meanwhile if caught in its early stage of lentigo maglina, there will be a high survival rate of it. So there is really in needed that people pay attention to skin situation and take regular examination. And people should learn and know how to use a dermoscopy correctly for self-examination. Any suspicious findings, have skin checked by professional doctors immediately. Early detection and treatment will bring better health for the skin.