OVERVIEW

What is melanoma?

Melanoma, also known as "malignant melanoma," is a highly malignant tumor. The affected skin often appears as an asymmetrical patch with uneven color, irregular borders, and a diameter usually greater than 6 mm^[1].

It commonly occurs on the soles of the feet, toes, fingertips, and under the nails but can also appear on mucous membranes in areas such as the rectum, anus, vulva, eyes, mouth, nose, and throat. It often leads to ulceration, causing symptoms like bleeding, pain, and obstruction^[1].

The exact cause of melanoma is not fully understood, but it may be related to factors such as race, genetics, trauma, chemical carcinogens, excessive sun exposure, and immune function. Men are more likely to develop it than women^[1].

Surgical removal is the ideal treatment for early-stage, non-metastatic melanoma, and most cases can be cured with surgery. If metastasis occurs, chemotherapy or a combination of surgery and chemotherapy may be used, but the prognosis is poor, and a complete cure is usually unattainable^[2].

Is melanoma common? Can it be fatal?

Melanoma is more common in Western countries, with lighter-skinned populations at higher risk^[3]. It predominantly affects people over 50 years old, is rare in children, and is 1.6 times more common in men than women^[4].

Currently, melanoma has become the fastest-growing malignancy in terms of incidence among all cancers, with an annual increase rate of about 3%–5%^[3]. In China, the incidence rate in 2017 was approximately 0.9 per 100,000, meaning about one in every 100,000 people may develop the disease^[5].

What are the common types of melanoma?

Melanoma is commonly classified into four types: acral lentiginous melanoma, lentigo maligna melanoma, nodular melanoma, and superficial spreading melanoma^[6].

• Acral lentiginous melanoma: The most common type in China, often developing from acral lentiginous nevi. It typically occurs on the palms, soles, nails, and periungual areas. The lesions appear as irregularly bordered, unevenly pigmented patches. This type progresses rapidly and is prone to metastasis.
• Lentigo maligna melanoma: Commonly found on sun-exposed areas in older adults, usually arising from lentigo maligna. This type grows slowly and metastasizes late.
• Nodular melanoma: Frequently appears on the head, neck, trunk, soles, vulva, and lower limbs.
• Superficial spreading melanoma: Develops from superficial melanoma and is most common on the trunk and limbs.

SYMPTOMS

What are the manifestations of acral lentiginous melanoma? What does a black spot under the nail mean?

Acral lentiginous melanoma is the most common type in China, accounting for 50% of melanomas in Asians^[1]. It often appears on the toes, soles, and fingers of elderly individuals, particularly under the fingernails or toenails. The lesion presents as an asymmetrical, irregularly bordered, unevenly colored brown or black patch, usually exceeding 6 mm in diameter, and continues to enlarge. Some patients may develop ulceration. It grows rapidly, metastasizes early, often swells in a short time, and forms ulcers, with a low 5-year survival rate of only 5%–11%^[3].

There are many possible causes of black spots under the nail, the most common being subungual hematoma, followed by nail matrix nevus, melanonychia, nail staining, and malignant melanoma. Therefore, there is no need to panic at the sight of a black spot under the nail. In fact, the vast majority of such spots are benign, with malignant melanoma being extremely rare.

What are the manifestations of lentigo maligna melanoma?

Lentigo maligna melanoma primarily affects the elderly and commonly occurs on sun-exposed areas, such as the face^[6]. It often evolves from lentigo maligna.

The lesion appears as a light brown or unevenly colored brown patch with irregular borders, gradually expanding outward. Small black spots may sometimes be seen around the patch. The lesion grows slowly, and metastasis occurs relatively late.

What are the manifestations of nodular melanoma?

Nodular melanoma often appears on the soles, head, neck, torso, and genitals^[1]. It frequently develops from lentigo maligna.

The lesion initially presents as a blue-black or brown nodule, which rapidly enlarges and may ulcerate. The lesion grows quickly and metastasizes early to the liver, lungs, and brain.

What are the manifestations of superficial spreading melanoma?

Superficial spreading melanoma, also known as pagetoid melanoma, often appears on the back and lower legs. It typically evolves from lentigo maligna.

The lesion appears as an uneven patch of tan, brown, pink, blue, or black, usually no larger than 2.5 cm in diameter. If the lesion ulcerates or hardens, it suggests a poor prognosis^[6]. The lesion grows slowly.

How can melanoma be detected early? Are irregular shapes, uneven colors, and enlarging lesions always dangerous?

Most melanomas arise from the malignant transformation of pigmented moles, so closely monitoring changes in moles is crucial for early detection. Seek medical attention promptly if a mole exhibits the following^[7]:

• Change in shape, such as asymmetry in a previously round or oval mole.
• Irregular borders, appearing jagged or scalloped.
• Uneven or changing color.
• Diameter exceeding 6 mm.
• Rapid changes in color, size, or shape.

Of course, not every minor change in a mole indicates malignancy, so there’s no need to overreact. A specialist should diagnose whether it is malignant.

CAUSES

What are the causes of melanoma?

The exact causes of melanoma are not yet fully understood. Researchers believe that the development of melanoma is closely related to the following factors^[1,4]:

• Race and genetics: The incidence of melanoma is higher in Caucasians than in Black individuals. About 3%–10% of melanoma patients have a family history, which may be related to the inheritance of sun-sensitive genes or specific melanoma susceptibility genes^[1,4].
• Trauma and artificial stimulation: Excessive stimulation of benign pigmented moles (repeated scraping or removal) and physical trauma may cause benign moles to become malignant^[1].
• Viral infection: Signs of viral infection have been found in some melanoma patients^[1].
• Excessive sun exposure: Overexposure to sunlight increases the risk of melanoma. Long-term excessive ultraviolet (UV) radiation may induce gene mutations, thereby triggering the disease^[4].
• Immune factors: Reduced immunity or the use of immunosuppressants (such as dexamethasone, methylprednisolone, azathioprine, etc.) weakens the body's ability to kill tumor cells, allowing tumor cells to proliferate unchecked and invade the body^[1,4].
• Environment: Exposure to chemical carcinogens, such as dyes, asphalt, and soot.

Who is more likely to develop melanoma?

• Individuals with a family history: The onset of melanoma is related to the inheritance of susceptibility genes, and the risk is significantly higher in those with a family history^[1].
• Individuals with long-term UV exposure: Those living in sun-rich areas or near the equator may develop melanoma due to prolonged UV exposure inducing gene mutations^[1].
• Patients with benign melanocytic tumors: Benign melanocytic tumors such as dysplastic nevi or congenital giant nevi have a certain chance of progressing to melanoma, making these individuals more susceptible.
• Immunocompromised individuals: People with precancerous conditions, cancer, immunosuppression, or organ transplants have a higher risk due to weakened immune function^[1].
• Middle-aged and elderly men: Men, especially those over 50, have a higher risk compared to women^[4].

Under what circumstances is melanoma more likely to become malignant?

• Frequent friction, pressure, or picking.
• Moles that recur after multiple laser treatments.
• Large pigmented moles, such as those exceeding 10 mm in diameter.

Is melanoma contagious?

No, melanoma is a highly malignant tumor but is not contagious.

Is melanoma hereditary?

There is a genetic predisposition. Studies show that about 3%–10% of melanoma patients have a family history, meaning that in every 100 melanoma patients, 3–10 have relatives with the disease^[1].

DIAGNOSIS

What tests are needed for melanoma?

• Physical examination: Through visual inspection, observe the location and morphology of the patient's skin lesions to preliminarily understand the condition. The examination may reveal irregular black patches or moles, possibly accompanied by uneven coloration.
• Pathological examination of skin lesions: This is the main basis for diagnosing the disease. The examination may reveal scattered or nested melanoma cells in the epidermis and dermis, spreading horizontally and vertically, extending deep into the dermis and subcutaneous tissue^[1].
• Immunohistochemical testing: This test can provide a definitive diagnosis of the disease. Both anti-S-100 protein and anti-HMB-45 monoclonal antibody staining results are positive^[1].
• Imaging tests: Including ultrasound, X-ray, CT, etc., which are determined based on the patient's specific condition, mainly used to screen for lymph node metastasis and guide subsequent treatment.

How to differentiate melanoma from pigmented nevus?

Melanoma generally appears in people over 50 years old. The affected skin is asymmetrical, with irregular edges, uneven coloration, and a diameter often exceeding 6 mm.

Pigmented nevus, on the other hand, can be congenital or acquired. The affected skin is more regular, appearing as round, flat, hemispherical, etc., with a smooth surface and slow growth, usually without any sensation. The above characteristics can help differentiate the two. Of course, the final distinction relies on a doctor's judgment, and if necessary, a skin biopsy may be performed.

How to differentiate melanoma from age spots?

Melanoma generally appears in people over 50 years old. The affected skin is asymmetrical, with irregular edges, uneven coloration, and a diameter often exceeding 6 mm.

Age spots, however, mostly appear on the face, back of hands, chest, back, etc. The affected skin is oily, as if stuck to the skin, with clear edges and round, oval, or irregular patches. The two can be differentiated based on these specific characteristics of the affected area.

TREATMENT

Which department should I visit for melanoma?

This condition is generally treated in the Dermatology and Venereology or Oncology department.

How is melanoma treated?

• Surgical treatment: The ideal treatment for early-stage melanoma without metastasis. Surgical methods include wide excision, sentinel lymph node biopsy, and lymph node dissection^[2]. Surgery is the primary treatment for melanoma. If the tumor can be completely removed, surgery should be performed. The advantage is thoroughness, but the downside is incomplete resection in some cases, leading to recurrence. Some patients may not be suitable for surgery.
• Chemotherapy: For patients with metastatic advanced-stage melanoma, chemotherapy or combination therapy may be chosen^[1]. Common drugs include dacarbazine and cisplatin.
• Radiotherapy: Mainly used for patients with bone or central nervous system metastases. It can alleviate symptoms caused by visceral or central nervous system metastases and relieve pain from bone metastases^[1].
• Immunotherapy: Includes injections of polyvalent cell vaccines, peptide vaccines, interleukin, and interferon. Some reports suggest significant efficacy in certain patients, inhibiting melanoma growth. However, side effects like fatigue, fever, and liver/kidney dysfunction may occur^[2]. Currently, immune checkpoint inhibitors like PD1 show promising results in treating malignant melanoma.

Malignant melanoma is considered a radiation-resistant tumor, making radiotherapy less effective. However, radiotherapy may be attempted if surgery is incomplete, recurrence occurs, the patient refuses surgery, or the tumor is too large for surgery, potentially extending survival time.

Advanced melanoma is difficult to cure, with no highly effective treatments available. Dacarbazine has long been the "gold standard" for chemotherapy, often combined with surgery or other drugs like vinblastine, cisplatin, and bleomycin for better results. However, side effects like nausea, vomiting, hair loss, and liver/kidney damage are common, and it is only effective for some patients^[7].

What does melanoma surgery involve?

Wide excision: Removes the entire skin lesion and subcutaneous tissue down to the muscle fascia, suitable for most patients^[2]. Pros: Removes the tumor and improves symptoms. Cons: Improper postoperative care may lead to complications like bleeding or infection.

Sentinel lymph node biopsy and lymph node dissection: A biopsy of lymph nodes to check for metastasis. If metastasis is found, lymph node dissection is performed^[2]. Pros: Prevents further spread and improves survival rates. Cons: Improper care may cause bleeding, fluid accumulation, or infection.

What preparations are needed before melanoma surgery?

Preoperative tests include blood tests, coagulation function, liver/kidney function, syphilis, and HIV screening to rule out contraindications. Patients should rest well the night before and avoid excessive stress.

When is surgery necessary for melanoma?

Surgery is the primary treatment if the tumor can be completely removed^[1,2]. Specific cases include:

• Early-stage melanoma without metastasis.
• Advanced melanoma with local metastasis (tumor cells invading nearby tissues and lymph nodes).
• Advanced cases with distant metastasis, where surgery may still improve quality of life.

When is surgery not suitable for melanoma?

Surgery is not recommended for patients with distant metastasis (e.g., to the lungs or gastrointestinal tract) who are in poor health or elderly.

Why is amputation sometimes necessary for melanoma?

For acral melanoma (e.g., toes, soles, fingers), if necrosis or ulceration occurs and other treatments fail, amputation may be needed to prevent further metastasis and save the patient's life.

How is chemotherapy administered for melanoma?

Systemic chemotherapy involves oral or intravenous drugs. Alone, it is often ineffective, so combination therapy is preferred. Dacarbazine is the most effective drug, sometimes combined with vinblastine, cisplatin, or bleomycin, but it only works for some patients^[4,7].

Isolated limb perfusion: Used for acral melanoma. Chemotherapy drugs are injected into the tumor's blood supply while a tourniquet restricts circulation, targeting the tumor directly and avoiding amputation^[6].

Does chemotherapy accelerate death in melanoma patients?

No. Chemotherapy is a key treatment for melanoma. Despite side effects like nausea, vomiting, or hair loss, it remains crucial, especially for advanced cases or patients unsuitable for surgery.

How is radiotherapy administered for melanoma?

Radiotherapy uses high-energy X-rays, gamma rays, or ion beams to kill tumor cells. It can be used alone or combined with chemotherapy or surgery.

Does radiotherapy accelerate death in melanoma patients?

No. While side effects like radiation dermatitis, esophagitis, nausea, or vomiting may occur, the benefits (killing tumor cells) outweigh the risks.

If chemo/radiotherapy kills melanoma cells, why isn’t the tumor eliminated?

Tumor recurrence is complex. While most cells are killed, some enter a dormant state, evading treatment. After therapy ends, these cells may reactivate, causing recurrence.

Can melanoma patients access targeted therapy?

Yes. Ipilimumab and vemurafenib, FDA-approved targeted drugs, are effective for some patients but are not yet widely available in some countries. Ipilimumab improves survival rates, while vemurafenib treats BRAF-mutated, unresectable metastatic melanoma. Further research may expand their use.

Can melanoma be completely cured?

Early-stage, non-metastatic melanoma can be cured. Advanced metastatic melanoma is difficult to cure^[2].

What is the life expectancy for melanoma patients?

Early-stage patients can live normally with timely treatment. For advanced cases, the 5-year survival rate is only 16%^[3], emphasizing the importance of early detection and treatment.

What treatments are available if chemo/radiotherapy aren’t options?

Immunotherapy (e.g., polyvalent vaccines, interleukin, interferon) may be tried, though efficacy varies^[2].

Can melanoma recur after treatment? How to prevent it?

Early-stage melanoma rarely recurs after cure. Advanced cases often recur^[2,6]. Currently, no effective prevention methods exist.

DIET & LIFESTYLE

What should be noted in postoperative care for melanoma?

Change dressings regularly, avoid getting the incision wet before stitches are removed, and refrain from strenuous exercise.

What should melanoma patients pay attention to in their diet? Can they consume soy sauce or dark-colored foods?

Melanoma patients should follow a high-protein, low-fat diet, maintain balanced nutrition, and consume plenty of vegetables and fruits. They should also include high-quality protein sources such as fish, chicken, milk, and legumes^[8]. Soy sauce or other dark-colored foods are unrelated to the pigment in moles or tumors and can be consumed normally—popular myths have no scientific basis.

What should melanoma patients pay attention to in daily life?

• Stay optimistic, cheerful, and maintain a happy mood.
• After treatment and recovery, maintain a regular routine and balance work with rest.
• Engage in moderate aerobic exercise, such as jogging or cycling.
• Attend regular follow-up appointments.

PREVENTION

How to Prevent Melanoma? Can Moles Be Scraped or Repeatedly Removed?

• Avoid sun exposure as much as possible and take daily sun protection measures.
• Keep the skin clean and minimize skin trauma to prevent infection.
• Avoid direct skin contact with harmful chemicals. If necessary, use protective gear such as masks and gloves.
• High-risk groups should undergo regular check-ups, pay attention to melanoma symptoms, and achieve early detection, diagnosis, and treatment.
• For pigmented moles in friction-prone areas, a biopsy can be performed for pathological examination.
• Avoid irritating moles by scraping, picking, needling, using corrosive chemicals, freezing, or laser treatments, as trauma may trigger malignant transformation.