--- title: Melanoma url: "https://www.yyhmedical.com/en/guide/solid/disease-melanoma" type: MedicalWebPage inLanguage: en-US --- # Melanoma > Melanoma is a cancer that develops from melanocytes, the cells that produce pigment. It most commonly occurs in the skin but can also develop beneath the nails, in the eye, and in mucosal tissues such as the mouth, nasal passages, gastrointestinal tract, and genitourinary tract. Different melanoma subtypes can have distinct risk factors, molecular features, and treatment approaches. ## Overview Melanoma develops from melanocytes. These cells are found mainly in the skin but are also present in the eye and certain mucosal tissues, so melanoma is not limited to the skin. Common growth patterns of cutaneous melanoma include superficial spreading melanoma, nodular melanoma, lentigo maligna melanoma, and acral lentiginous melanoma. Acral melanoma develops on the palms, soles, fingers, toes, or beneath the nails and is particularly important to recognize in Asian populations. Mucosal melanoma can arise in areas such as the nasal cavity, mouth, anorectal region, and female genital tract. Its biology and molecular features differ from those of cutaneous melanoma, so treatment strategies may also differ. Most melanomas do not develop from an existing common mole. They can arise from a pre-existing nevus, but more often appear in previously normal-looking skin. ## Causes and Risk Factors Melanoma develops through a combination of genetic susceptibility, environmental exposures, and acquired genetic changes in melanocytes. Risk factors differ among melanoma subtypes. For cutaneous melanoma, ultraviolet radiation is an important risk factor, particularly repeated severe sunburns and exposure to artificial UV sources. Other risk factors include having many or atypical moles, a personal or family history of melanoma, certain inherited genetic changes, and immunosuppression. UV exposure is not equally important for all melanoma subtypes. Acral and mucosal melanomas, for example, are less strongly linked to ultraviolet radiation. There is not good evidence that repeated rubbing, scratching, minor trauma, or removal of a mole causes a benign mole to become melanoma. ## Signs and Symptoms Cutaneous melanoma may appear as a new pigmented lesion or as a noticeable change in an existing mole. The “ABCDE” rule is commonly used to recognize suspicious lesions: - A — Asymmetry: one half looks different from the other. - B — Border: irregular, blurred, or notched edges. - C — Color: multiple colors within one lesion or a noticeable change in color. - D — Diameter: a larger lesion may raise concern, but melanomas can also be smaller than 6 mm. - E — Evolving: changes in size, shape, color, thickness, or symptoms over time. A new lesion that looks very different from a person's other moles should also be evaluated. Other warning signs may include itching, pain, bleeding, crusting, ulceration, or a lesion becoming raised. **Acral and Subungual Melanoma** Acral melanoma develops mainly on the palms, soles, fingers, toes, or beneath the nails. On the soles, it may appear as an enlarging brown or black patch with irregular borders and uneven color. Some lesions may become raised, ulcerated, or bleed. Subungual melanoma may appear as a longitudinal pigmented band beneath a fingernail or toenail that gradually becomes wider or more irregular. Pigment may sometimes extend onto the surrounding skin. Not every dark spot or streak beneath a nail is melanoma. Bruising after injury, benign nail matrix nevi, and other pigment changes are much more common. A changing or widening band, nail distortion, or pigment extending onto nearby skin should be medically evaluated. ## Diagnosis When melanoma is suspected, the doctor examines the lesion's size, color, borders, symmetry, and changes over time. Dermoscopy is often used to evaluate suspicious skin lesions more closely. A tissue biopsy is required to establish the diagnosis. When feasible, a suspicious cutaneous lesion is usually completely removed with a narrow initial margin for diagnostic biopsy. This allows the pathologist to accurately assess important features such as Breslow thickness and ulceration. Pathology reports commonly include Breslow thickness, ulceration, margin status, and other features that affect staging and treatment. Immunohistochemistry may support the diagnosis using markers such as SOX10, S100, Melan-A, and HMB45, but diagnosis is based on the overall pathologic findings rather than any single marker. For selected patients with a melanoma that carries a meaningful risk of lymph node spread, sentinel lymph node biopsy may be considered at the time of definitive surgery. It helps identify microscopic lymph node involvement and guides staging and treatment decisions. Patients with higher-risk or more advanced disease may also need ultrasound, CT, PET/CT, brain MRI, or other imaging. Molecular testing is increasingly important. BRAF testing can guide treatment for advanced and selected high-risk melanoma, while other alterations such as KIT may be relevant in some acral or mucosal melanomas. ## Treatment Treatment depends on the primary site, stage, surgical findings, lymph node and distant spread, and molecular features such as BRAF status. Surgery remains the main treatment for early-stage melanoma, while higher-risk and advanced disease may require a combination of surgery, immunotherapy, targeted therapy, radiation therapy, and other local treatments. For localized cutaneous melanoma, wide local excision is the standard treatment. Surgical margins are based on pathologic features such as Breslow thickness. Sentinel lymph node biopsy may also be recommended for selected patients. Patients with completely resected stage IIB, IIC, or certain stage III melanomas may be candidates for adjuvant immunotherapy to reduce the risk of recurrence. For some patients with resectable stage III disease, immunotherapy may also be given before surgery as part of a neoadjuvant or perioperative approach. For unresectable stage III, stage IV, or recurrent melanoma, immunotherapy and targeted therapy are now the major systemic treatment approaches. PD-1 inhibitors such as pembrolizumab and nivolumab are important options. Combination immunotherapy, including nivolumab plus ipilimumab or nivolumab plus relatlimab, may be appropriate for selected patients, although combination therapy can cause more immune-related side effects. For melanomas with a BRAF V600 mutation, combined BRAF and MEK inhibition is an important targeted treatment approach. Examples include dabrafenib plus trametinib and encorafenib plus binimetinib. Radiation therapy may be used for selected local tumors, high-risk areas after surgery, or metastatic lesions, particularly those involving the brain or bone. Traditional chemotherapy such as dacarbazine has a much smaller role today because immunotherapy and targeted therapy have substantially changed the treatment of advanced melanoma. ## Content attribution (YMYL) - Author: - Medically reviewed by: - Last reviewed: - First published: > --- Original (HTML):https://www.yyhmedical.com/en/guide/solid/disease-melanoma This is a clean Markdown mirror for large language models; the original page is authoritative.