Punch Biopsy

1. Indications: Full thickness skin specimen
   1. Diagnosis of Inflammatory skin diseases
   2. Diagnosis of neoplasms
   3. Systemic Lupus Erythematosus or Discoid Lupus
   4. Lichen Planus
   5. Drug Eruptions (Requires depth)
2. Determining optimal biopsy site
   1. Macule
      1. Biopsy area most abnormal in color
      2. Advance punch into subcutaneous fat
   2. Papule
      1. Excise completely if possible
      2. Biopsy larger Papules through thickest area
   3. Plaque
      1. Biopsy through thickest area
      2. Advance punch into subcutaneous fat
   4. Nodule or tumor
      1. Biopsy through thickest area
      2. Advance punch into subcutaneous fat
   5. Vesicle
      1. Excise Vesicle intact to optimize histology
   6. Bulla
      1. Biopsy at edge of Blister including Blister roof
3. Technique
   1. Mark area of lesion to biopsy with surgical marker
      1. Select most abnormal portion of lesion
   2. Determine Punch Biopsy size (2-6 mm)
   3. Administer local anesthetic
   4. Prepare and drape area for incision
   5. Stretch skin perpendicular to Skin Tension Lines
   6. Rotate skin punch into Dermis
      1. Remove punch when it enters subcutaneous fat
      2. Beware of superficial neurovascular structures
   7. Elevate specimen above incision
      1. Use sterile 21 gauge needle
      2. Avoid forceps due to crush injury of specimen
   8. Cut specimen free on undersurface with iris scissors
   9. Close lesion
      1. No closure needed if 3 mm punch or less used
      2. Healing by Secondary Intention for small excisions offers equivalent cosmetic results as with Suture
   10. Top lesion with Bacitracin and bandage
4. Complications
   1. Injury to underlying nerves or vessels
5. References
   1. Pariser (1989) Modern Medicine 57:82-90
   2. Snell in Pfeninger (1994) Procedures, p. 20-6
   3. Zuber (2002) Am Fam Physician 65(6):1155-68