The Bottom Line

An excisional biopsy is a minor surgical procedure where your dermatologist removes an entire suspicious skin lesion — a mole, growth, or spot — along with a small margin of normal surrounding skin. The removed tissue is then examined under a microscope by a pathologist to determine whether it is benign (harmless), pre-cancerous, or cancerous. It is both a diagnostic test and, in many cases, a complete treatment — if the lesion is fully removed with clear margins, no further surgery may be needed.

What Is an Excisional Biopsy?

An excisional biopsy is a procedure in which your dermatologist completely removes a skin lesion — such as a mole, growth, cyst, or suspicious spot — together with a small rim of surrounding normal skin (called a "margin"). This is different from a shave biopsy (which shaves off a superficial layer) or a punch biopsy (which removes a small cylindrical core). With an excisional biopsy, the entire lesion is taken out in one piece.

The removed tissue is sent to a pathology laboratory, where a dermatopathologist examines it under a microscope to determine exactly what it is. Results typically take 5–14 business days.

Excisional biopsy is the preferred technique for lesions that are suspicious for melanoma (the most serious type of skin cancer) or other conditions where removing the entire lesion and examining its edges (margins) is medically important.

Why Would Your Dermatologist Recommend an Excisional Biopsy?

Your dermatologist may recommend an excisional biopsy if you have a skin lesion that:

  • Has features suspicious for melanoma — asymmetry, irregular borders, multiple colors, large diameter (>6 mm), or recent changes (the ABCDEs of melanoma)
  • Has changed in size, shape, or color
  • Bleeds, itches, or doesn't heal
  • Is a mole with unusual features under dermoscopy (a magnifying tool dermatologists use)
  • Needs complete removal for an accurate diagnosis — particularly when the whole lesion architecture matters
  • Is a cyst, lipoma, or benign growth that is causing symptoms and needs removal anyway

What Happens During the Procedure

An excisional biopsy is performed in your dermatologist's office under local anesthesia — you are fully awake but feel no pain. Here's what to expect:

Anesthesia: Your doctor injects a small amount of local anesthetic (usually lidocaine) around the lesion. You will feel a brief stinging sensation from the injection, and then the area goes numb within 1–2 minutes.

Removal: Using a scalpel, your dermatologist makes an elliptical (oval-shaped) incision around the lesion, including a margin of normal skin. The size of the margin depends on the type of lesion — for a suspicious mole, a 1–2 mm margin is typical for biopsy purposes.

Closure: The wound is closed with sutures (stitches). Most excisional biopsies result in a small linear scar. Sutures are typically removed 7–14 days later depending on the location (face heals faster than the back or legs).

The entire procedure usually takes 15–30 minutes. You can drive yourself home and return to most normal activities the same day, with a few restrictions (no heavy exercise, keep the wound dry for 24–48 hours).

Recovery and Wound Care

After your excisional biopsy, your dermatologist will give you specific wound care instructions. In general:

  • Keep the wound covered with a bandage and apply petroleum jelly (Vaseline) or antibiotic ointment daily to promote healing and minimize scarring
  • Keep the area clean — gently wash with mild soap and water once daily
  • Avoid submerging the wound (swimming, baths) until it is fully healed
  • Limit strenuous activity and heavy lifting for 1–2 weeks to prevent the wound from reopening
  • Watch for signs of infection: increasing redness, swelling, warmth, pus, or fever — call your doctor if these develop

Most excisional biopsy wounds heal within 2–4 weeks. A small scar will remain, which fades over 6–12 months. Scars on the face generally fade better than those on the back or lower legs.

Understanding Your Results

When your pathology report comes back, the result will either be benign (no further treatment needed), pre-cancerous (may need re-excision with wider margins), or malignant (cancer requiring additional treatment). The report will also state whether your margins are "clear" (no abnormal cells at the edge of what was removed) or "involved" (abnormal cells extend to the margin, meaning re-excision is recommended).

If your margins are clear and the lesion is fully removed, no further surgery is needed. Your dermatologist will advise on follow-up skin checks depending on the diagnosis.

Frequently Asked Questions

Will the excisional biopsy leave a scar?

Yes — any procedure that cuts through the full thickness of skin will leave a scar. Excisional biopsies leave a small linear scar. However, proper wound care, keeping it moisturized and protected from sun exposure, significantly reduces how visible the scar becomes. Most scars fade substantially over 6–12 months and are a worthwhile tradeoff for an accurate diagnosis and complete lesion removal.

Does an excisional biopsy hurt?

The injection of local anesthetic causes brief stinging — usually just a few seconds. The procedure itself is painless. After the anesthetic wears off (2–4 hours), you may experience mild soreness for 1–3 days, easily managed with over-the-counter acetaminophen. Most patients describe the discomfort as minimal.

How long until I get my biopsy results?

Pathology results from a standard excisional biopsy typically take 5–14 business days. Your dermatologist or their office will contact you with results. If you haven't heard back within two weeks, it's reasonable to call the office to follow up.

What if the pathology shows cancer?

If your biopsy shows a skin cancer, your dermatologist will discuss the next steps based on the type and depth. For basal cell or squamous cell carcinomas with clear margins, no further treatment may be needed. For melanoma or cancers with involved margins, re-excision with wider margins or other treatments will be recommended. Most skin cancers detected and treated early have excellent cure rates.

References

  1. Swetter SM, Tsao H, Bichakjian CK, et al. Guidelines of care for the management of primary cutaneous melanoma. J Am Acad Dermatol. 2019;80(1):208-250.
  2. Brodland DG, Zitelli JA. Surgical margins for excision of primary cutaneous squamous cell carcinoma. J Am Acad Dermatol. 1992;27(2):241-248.
  3. Balch CM, Gershenwald JE, Soong SJ, et al. Final version of 2009 AJCC melanoma staging and classification. J Clin Oncol. 2009;27(36):6199-6206.
  4. Aasi SZ, Leffell DJ. Biopsy techniques in dermatology. Fitzpatrick's Dermatology in General Medicine. 8th ed. McGraw-Hill; 2012.
  5. Hieken TJ, Hernandez-Irizarry R, Boughey JC, et al. Accuracy of diagnostic biopsy for cutaneous melanoma. Arch Surg. 2013;148(7):679-684.
  6. Ng JC, Swain S, Dowling JP, et al. The impact of partial biopsy on histopathologic diagnosis of cutaneous melanoma. Arch Dermatol. 2010;146(3):234-239.