How should I evaluate and manage an enlarging nevus that is bleeding after a minor scratch injury?

Urgent Excisional Biopsy Required for Enlarging, Bleeding Nevus

An enlarging nevus that is bleeding after minor trauma requires urgent complete excisional biopsy with 2mm margins to rule out melanoma, as bleeding is a recognized warning sign of malignancy regardless of trauma history.

Critical Warning Signs Present

Your lesion demonstrates two major red flags from the ABCDE criteria for melanoma 1:

• E (Evolution): Recent change in size
• Bleeding: Listed as a minor criterion for melanoma suspicion

While trauma can cause bleeding in benign nevi, the combination of increasing size PLUS bleeding warrants immediate evaluation 1. The trauma may be coincidental rather than causative.

Immediate Action Required

Refer urgently to dermatology or a surgeon with expertise in pigmented lesions within 2 weeks 2. The specialist should:

1. Perform full skin examination - document all pigmented lesions and check for lymphadenopathy 2

2. Complete excisional biopsy - NOT a shave, punch, or partial biopsy 1, 2:

   • Full-thickness excision with 2mm clinical margin of normal skin
   • Include subcutaneous fat
   • Orient incision along skin lines for potential re-excision
   • Send entire specimen for histopathology

3. Clinical photography before excision 2

Why Excisional Biopsy is Mandatory

Partial biopsies (shave/punch) are contraindicated because they 1, 2:

• Risk misdiagnosis through sampling error
• Make accurate Breslow thickness measurement impossible
• Compromise staging if melanoma is present
• Cannot assess all histological parameters

Important Caveats About Trauma

While traumatized benign nevi can show concerning features 3:

• Pagetoid spread limited to trauma site (20% of cases)
• Parakeratosis (92%)
• Dermal inflammation (49%)

However, these findings should NOT delay biopsy. The histopathologist needs to know about the trauma history, but clinical suspicion based on size increase and bleeding takes precedence 3.

What Makes This High Priority

The 2012 ESMO guidelines emphasize that bleeding is specifically listed among the seven criteria for melanoma suspicion (three major: change in size, color, shape; four minor: diameter >7mm, hypersensitivity, bleeding, inflammation) 1. Your lesion has at least two concerning features.

Do not wait to "see if it heals" - the scratch injury does not explain the size increase, and melanomas can present with bleeding after minor trauma 1.

What to Tell Your Doctor

Provide specific details:

• Timeline of size increase (weeks? months?)
• Exact size now vs. before
• Any color changes
• Previous appearance of this mole
• Family history of melanoma
• Personal history of other atypical moles

The pathology report must include 4, 5:

• Breslow thickness (to 0.1mm)
• Presence of ulceration
• Mitotic rate
• Margin clearance
• AJCC staging

Bottom line: Size increase + bleeding = excisional biopsy now, regardless of trauma history 1, 4, 1, 2.