What are the next steps for an adult patient with a history of skin lesions or previous melanoma, who has a pathology report showing a dermal scar but no residual melanocytic proliferation?

Management of Dermal Scar with No Residual Melanocytic Proliferation

A pathology report showing only dermal scar with no residual melanocytic proliferation after excision of a melanocytic lesion indicates complete removal and requires routine surveillance based on the original lesion characteristics, not additional immediate intervention. 1

Interpretation of This Pathology Result

This pathology finding represents one of two clinical scenarios:

• Complete excision of a benign melanocytic nevus: The scar tissue indicates the lesion was fully removed with no remaining melanocytic cells 2
• Complete excision after previous melanoma treatment: If this represents re-excision of a melanoma site, the absence of residual melanocytic proliferation confirms adequate surgical margins 1

The key distinction is whether this represents a true local scar recurrence (with in situ and/or radial growth phase present) versus simply scar tissue—your pathology shows neither melanoma nor melanocytic proliferation, which is reassuring. 1

Immediate Next Steps

No Additional Surgery Required

• No re-excision is needed since there is no residual melanocytic proliferation and margins are clear 1
• The dermal scar alone does not warrant further surgical intervention 1

Determine Surveillance Protocol Based on Original Lesion

If the original lesion was a benign nevus:

• Annual full-body skin examination for life 1
• Monthly self-examination of skin and lymph nodes 3
• No routine imaging required 1

If the original lesion was melanoma Stage IA-IIA:

• History and physical examination with emphasis on regional lymph nodes and skin every 3-12 months for 5 years, then annually 1
• Routine radiologic imaging is not recommended for these stages 1
• Monthly self-examination of skin and lymph nodes 3

If the original lesion was melanoma Stage IIB-IV:

• History and physical examination every 3-6 months for 2 years, then every 3-12 months for 3 years, then annually 1
• Consider chest x-ray, CT, and/or PET/CT scans every 6-12 months to screen for recurrent/metastatic disease (category 2B recommendation) 1
• Consider brain MRI annually (category 2B) 1
• Routine imaging not recommended after 5 years 1

Critical Surveillance Elements

What to Monitor During Follow-up Visits

• Skin examination: Look for new or changing pigmented lesions, particularly asymmetric lesions with irregular borders, color variation, diameter >6mm, or evolving characteristics 4, 5
• Regional lymph nodes: Palpate for any enlargement or firmness in the nodal basin draining the original lesion site 1
• Scar site: Examine for any new pigmentation, nodularity, or satellite lesions within 2cm of the scar 1

Patient Education Points

• Instruct on monthly self-skin examination technique, emphasizing the scar site and regional lymph nodes 3
• Educate about sun protection: avoid tanning beds, limit sun exposure during peak hours (10 AM-4 PM), use sunscreen and protective clothing 4
• Warn that if new pigmentation appears in the scar, immediate evaluation is required 2
• Inform that family members have 4-8% lifetime risk of developing melanoma 3

Common Pitfalls to Avoid

Do Not Assume Recurrence Cannot Occur

• Even with clear pathology now, late recurrences (≥10 years) are documented for melanoma 1, 3
• New pigmentation in a scar after complete excision represents a different clinical scenario than your current finding and would require biopsy 1, 2

Do Not Order Routine Blood Tests or Imaging for Low-Stage Disease

• Routine blood tests (LDH, CBC) are not recommended for surveillance in any stage 1
• For Stage IA-IIA melanoma with no evidence of disease, routine radiologic imaging has extremely low yield and is not recommended 1

Recognize the Recurrent Nevus Phenomenon

• If new pigmentation appears in the scar months later, this could represent a "recurrent nevus" from incomplete removal of a benign lesion rather than melanoma 2
• However, any new pigmentation in a melanoma excision scar requires immediate biopsy to exclude true recurrence 1

Tailor Surveillance Intensity to Risk

• Surveillance intervals should be adjusted based on original tumor stage, with higher-stage disease requiring more frequent monitoring 1
• Patients with multiple atypical nevi, fair skin type, or family history of melanoma may warrant more frequent dermatologic surveillance 1, 3