Incisional Biopsy

1. Definition
   1. Full dermal thickness excision
2. Indications
   1. Diagnostic (e.g. Suspected malignancy)
      1. All pigmented lesions must be full thickness excision
      2. Melanoma therapy is based on lesion depth
   2. Complete excision of lesion for cure
   3. Cosmetic indications
3. Preparation: Excision path
   1. General
      1. 3:1 Elliptical Excision prevents dog ears at corner
   2. Mark planned excision before anesthesia injected
   3. Long axis should be parallel to Skin Tension Lines
   4. First mark intended width of excision
      1. Use minimal margin (1-2 mm)
      2. Perform wider excision later if biopsy positive
         1. Nodular Basal Cell Carcinoma: 3-4 mm margin
         2. Squamous Cell Carcinoma: 5 mm margin
         3. Malignant Melanoma: Margin varies per lesion depth
   5. Next mark intended length of excision
      1. Excision length should be 3 times the width
   6. Draw excision path (elliptical or fusiform)
      1. Connecting width and length points
      2. Corner angles should be 30 degrees
4. Procedure
   1. Clean site with Betadine or Hibiclens
   2. Anesthesize site with Local Lidocaine
   3. Drape excision site
   4. Excise lesion along drawn path with #15 blade
      1. Make each scalpel pass smooth and continuous
      2. Depth of excision should be to subcutaneous fat
      3. Blade should be vertical to skin
         1. "Build a pyramid - Do not dig a ditch"
         2. Do not angle blade inward toward lesion
            1. Slightly outward beveling preferred over inward
   5. Free corners of ellipse and work toward center
      1. Gently lift corner with skin hook or adson with teeth
      2. Release corner by cutting between Dermis and SQ fat
      3. Excise full dermal thickness to ellipse center
      4. Repeat to free other corner and excise to center
      5. Immediately place lesion in formalin when excised
   6. Obtain adequate hemostasis
   7. Undermine skin edges if larger excision (if Melanoma not suspected)
      1. Hold skin edge with skin hook
      2. Use horizontal blade or iris scissors
      3. Separate Dermis from subcutaneous fat
      4. Tissue relaxation of 1 cm requires 3 cm undermining
   8. Suture skin closed
      1. See Suture Selection
      2. Deep-buried interrupted VicrylSutures if needed
         1. Prevents seroma formation below lesion
      3. Simple interrupted Nylon Suture
   9. Remove residual blood from wound
      1. Gently squeeze lesion
      2. Apply direct pressure for 10 minutes
   10. Bandage wound site
       1. Apply antibiotic ointment
       2. Sterile bandage
5. Follow-up
   1. See Suture Removal Timing
6. References
   1. Snell in Pfenninger (1994) Procedures, Mosby, p. 24-5
   2. Orengo (2002) Otolaryngol Clin North Am 35:153-70
   3. Zuber (2003) Am Fam Physician 67(7):1539-54