What is the appropriate management for a 59-year-old woman with a rough, irregularly shaped, dark brown, nontender mole with well-defined edges and no erythema located below the bra line that has been unchanged for six months?

Excisional Biopsy is Indicated for This Lesion

Despite the lesion being unchanged for 6 months, this rough-textured, irregularly shaped mole should undergo complete excisional biopsy with a 2-mm margin of normal skin to definitively rule out melanoma. The irregular shape and rough texture are concerning features that warrant histopathological examination, regardless of stability over time 1.

Clinical Assessment and Rationale

The lesion demonstrates concerning features based on ABCDE criteria:

• Asymmetry: Not explicitly stated but implied by "irregularly shaped"
• Border irregularity: Present (irregularly shaped)
• Color: Single dark brown (less concerning than variegation)
• Diameter: Not specified but should be measured
• Evolution: Reportedly unchanged for 6 months

While the single color and lack of recent change are somewhat reassuring, the irregular shape and rough texture are red flags that cannot be dismissed 1. The absence of evolution does not exclude melanoma, as some melanomas can remain stable for periods before progressing.

Why Excision is Necessary

Cutaneous lesions should be excised rather than biopsied for three critical reasons 1:

1. If benign, no further treatment is needed
2. Partial examination risks misdiagnosis - sampling error could miss malignant areas
3. Complete examination is essential - all histological parameters, particularly maximum Breslow thickness, require evaluation of the entire lesion

Specific Excision Technique

Perform an elliptical excision under local anesthetic with a 2-mm clinical margin of normal skin around the visible lesion 1. The incision should be oriented with the long axis parallel to skin tension lines to facilitate potential re-excision with minimal skin loss if melanoma is confirmed.

Critical technical points:

• Use a scalpel (never laser or electrocautery, which destroys tissue and compromises diagnosis) 1
• Include full-thickness skin with subcutaneous fat 2
• Document excision margins in the operative note 1
• Send entire specimen for standard histopathological examination (no frozen sections) 1

Common Pitfalls to Avoid

Do not perform:

• Shave biopsy (makes pathological staging impossible) 2
• Punch biopsy (inadequate for complete assessment) 2
• Observation alone (irregular features mandate tissue diagnosis)

Do not be falsely reassured by:

• Lack of change over 6 months (melanomas can have periods of stability)
• Single color (melanoma can be monochromatic)
• Well-defined edges (not all melanomas have indistinct borders)
• Location below bra line (melanoma can occur anywhere)

What Happens After Excision

If histopathology confirms melanoma, re-excision with wider margins will be required based on Breslow thickness 3:

• In situ melanoma: 0.5-cm margins
• ≤1.0 mm thickness: 1.0-cm margins (Category 1)
• 1.01-2.0 mm thickness: 1.0-2.0 cm margins (Category 1)
• >2.0 mm thickness: 2.0-cm margins (Category 1)

If benign (such as seborrheic keratosis or atypical nevus), no further surgical treatment is needed, though clinical follow-up may be appropriate depending on the specific diagnosis 4.

Patient Age Consideration

At 59 years old, this patient is in the peak age range for melanoma diagnosis. New or changing pigmented lesions after puberty warrant particular attention 2. The rough texture is especially concerning as it may represent a nodular component or hyperkeratotic surface change.