How to manage a 34-year-old male patient with a black lesion on his left arm pending punch biopsy?

Management of a Black Skin Lesion Pending Punch Biopsy

For a 34-year-old male with a 0.3 cm black lesion on the left arm with history of previous infection but currently no signs of infection, the most appropriate management is to proceed with the scheduled punch biopsy while monitoring the site for any changes in appearance or symptoms.

Pre-Biopsy Assessment and Monitoring

The current clinical scenario presents a small (0.3 cm) black lesion on the left arm that was previously infected but now shows no signs of infection. While awaiting the scheduled punch biopsy, the following management approach is recommended:

• Document the lesion characteristics thoroughly:

  • Size (0.3 cm already noted)
  • Exact location on left arm
  • Border characteristics (regular vs irregular)
  • Color variations within the lesion
  • Elevation (flat, raised, or depressed)
  • Surface characteristics (smooth, rough, ulcerated)

• Consider photographic documentation to track any changes before the biopsy 1

• Instruct the patient to monitor for changes and report immediately if any of the following occur:

  • Increase in size
  • Change in color or shape
  • Return of infection signs (redness, warmth, pain, drainage)
  • Bleeding or ulceration

Appropriateness of Punch Biopsy

The planned punch biopsy is appropriate for this clinical scenario:

• For small (0.3 cm) pigmented lesions, a punch biopsy that encompasses the entire lesion is acceptable 2, 1
• The punch biopsy should be full-thickness, including a cuff of subdermal fat to allow for accurate diagnosis and staging 2
• For suspected melanoma, the punch biopsy should be 3-4 mm in diameter to ensure adequate sampling 1, 3

Biopsy Technique Considerations

When performing the punch biopsy on 8/22/25:

• Select a punch instrument that will encompass the entire 0.3 cm lesion plus a small margin 1
• Ensure the biopsy includes the full thickness of the lesion with subcutaneous fat 2
• Orient the excision to facilitate possible subsequent wide local excision if needed 2
• Avoid shave biopsy as it may compromise accurate depth assessment if the lesion is melanocytic 2, 1

Post-Biopsy Management Plan

After the biopsy is performed:

• Close the wound appropriately (typically with a single suture for a 3-4 mm punch) 1, 3
• Provide standard wound care instructions
• Ensure proper handling of the specimen:
  • Place directly into formalin
  • Handle minimally to avoid crush artifact 1
  • Include complete clinical information on the pathology request form 2

Pathology Request Information

The pathology request should include:

• Patient demographics
• Anatomic location (left arm)
• Clinical appearance (0.3 cm black lesion)
• History of previous infection
• Differential diagnosis considerations
• Type of procedure performed 1

Common Pitfalls to Avoid

• Inadequate sampling: Ensure the punch biopsy encompasses the entire lesion when possible 1
• Crush artifact: Handle the specimen gently 1
• Incomplete clinical information: Provide thorough history including the previous infection 2
• Inadequate depth: Make sure to include subcutaneous fat in the specimen 2

While awaiting biopsy results, continue to monitor the patient and ensure appropriate follow-up based on the pathology findings. The scheduled punch biopsy is the appropriate next step in management to determine the nature of this lesion.