Based on NIH | Can melanoma cause numbness in the affected skin or limb, and when should this symptom prompt urgent medical evaluation?

Short Answer

Yes, melanoma can sometimes be associated with numbness in the skin or limb, but this is uncommon and usually signals either spread to or pressure on nearby nerves, or a rare nerve‑infiltrating subtype; new or sudden numbness especially if it involves an entire arm or leg or is accompanied by weakness, trouble speaking, confusion, dizziness, or a severe headache should prompt urgent medical evaluation. ^{[1] [2]}

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How Melanoma Could Cause Numbness

• Local nerve invasion (perineural spread): Certain melanomas, particularly rare “neurotropic” variants and some lentigo maligna melanomas, can grow along or into nerves, leading to sensory loss, tingling, or numbness in the area the nerve supplies. This pattern has been reported to cause focal numbness (for example, around the chin when the mental nerve is involved). ^{[3] [4] [5] [6]}

• Regional spread to lymph nodes or soft tissues: When melanoma progresses, it can spread to lymph nodes and nearby structures, potentially causing pain, tingling, or numbness due to nerve compression. Common metastatic sites include lymph nodes, liver, lungs, bone, and brain, and involvement near nerve pathways can produce sensory changes. ^{[1] [7] [8]}

• Treatment‑related neuropathy: After lymph node surgery (sentinel node biopsy or complete dissection), some people develop persistent numbness or neuropathic pain because small sensory nerves are cut or irritated. Reported rates vary widely, and symptoms can last beyond a month in a minority of cases. ^{[9] [10]}

• Advanced or atypical presentations: As melanoma advances, the texture may become firm or painful, and in uncommon forms (like acral lentiginous melanoma on palms/soles or under nails), deeper growth may be near nerve‑dense areas, potentially contributing to altered sensation. ^{[11] [12]}

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When Numbness Is Concerning

• Urgent red flags: Sudden onset numbness, numbness involving an entire arm or leg, or numbness accompanied by weakness/paralysis, confusion, trouble talking, dizziness, or a sudden severe headache should prompt emergency care because these signs may indicate a stroke or brain involvement. ^{[2] [13]}

• Prompt office evaluation: Numbness that gradually begins or persists, spreads, affects both sides, comes and goes, or seems related to repetitive activity should be assessed soon by a clinician to determine the cause and plan testing. ^{[14] [15] [16]}

• Linked to a skin lesion: If numbness occurs in the same area as a changing mole or skin lesion, it could suggest deeper invasion along a nerve and deserves timely dermatologic and possibly neurologic evaluation. ^{[5] [3]}

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What Doctors May Do

• Clinical examination: Careful skin and neurologic exams to map the area of sensory change and identify any suspicious lesions or lymph node enlargement. ^{[17] [18]}

• Imaging and tests: Depending on findings, doctors may order MRI or CT to assess for nerve involvement, masses, or brain lesions, and may recommend biopsy of any suspicious skin or lymph node area. ^{[13] [8]}

• Management approach: If melanoma is confirmed, wide local excision is standard for localized disease, and adjuvant radiotherapy can be considered in neurotropic or perineural invasion cases because of higher local recurrence risk; systemic therapy is tailored if spread is present. ^[3]

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Other Possible Causes of Numbness

While melanoma‑related nerve involvement is possible, many cases of numbness come from non‑cancer causes, such as pinched nerves, carpal tunnel syndrome, diabetes‑related neuropathy, vitamin deficiencies, or peripheral nerve tumors of other types; evaluation helps distinguish these. ^{[8] [14]}

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Practical Guidance

• Act urgently for sudden, widespread, or neurologically complex numbness, as listed above. ^{[2] [13]}

• Seek timely evaluation for persistent or spreading numbness, especially if it is near a changing mole or prior melanoma surgery site. ^{[5] [9]}

• Track symptoms: Note onset, pattern (constant vs. intermittent), exact location, associated pain or weakness, and any nearby skin changes (size, shape, color, bleeding, or firmness). ^{[17] [11]}

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Quick Reference Table

Scenario	What it may mean	What to do
Sudden numbness of an entire arm/leg or with weakness, confusion, trouble speaking, dizziness, or severe headache	Possible stroke or brain involvement	Go to emergency care immediately. [2] [13]
Focal numbness near a changing mole/lesion	Possible local nerve invasion by melanoma	Arrange prompt dermatology/neurology evaluation. [5] [3]
Persistent numbness near prior lymph node surgery	Possible postoperative sensory nerve injury	Schedule clinic visit for assessment and symptom management. [9] [10]
Gradual, intermittent hand numbness with repetitive tasks	Possible entrapment neuropathy (e.g., carpal tunnel)	Office visit; ergonomic and diagnostic evaluation. [14] [15]
New firm, painful skin area with sensory change	Possible advanced local melanoma or other mass compressing nerves	Prompt clinical assessment and imaging as indicated. [11] [8]

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Key Takeaways

• Melanoma can cause numbness, but this is relatively uncommon and often suggests nerve involvement by the tumor or pressure from nearby spread. ^{[3] [5]}

• Do not ignore new numbness, especially when it is sudden, widespread, or paired with other neurologic symptoms seek urgent care. ^{[2] [13]}

• Persistent or focal numbness near a skin lesion should be evaluated soon to rule out perineural invasion or other causes. ^{[3] [5]}