When a dermatologist evaluates your skin for abnormal moles, lesions or rashes, he or she may have identified something suspicious about a particular growth. Patients often ask, “How can you tell that this growth is normal or not?” The education, training and expertise gleaned from medical school, internships, subspecialized residency training and years of experience evaluating these growths provides the dermatologist with this insight. When a growth appears abnormal on physical examination, a biopsy is often required. The purpose of the biopsy is to evaluate the cellular architecture to determine the nature of the growth. The results obtained by the biopsy guide the dermatologist through the next steps of the treatment process.
Why doesn’t the dermatologist remove the entire mole to begin with and save the extra step?
Biopsies are a required step in the process of diagnosis and treatment of a particular condition. In the case of moles, moles are graded histologically on a scale of benign, mild atypia, moderate atypia, severe atypica and melanoma. Where the mole falls on this spectrum determines how much additional skin removal is required. If the biopsy results in a diagnosis of melanoma, removal of 0.5cm to 2.0cm margin of normal skin may be necessary to clear the area of melanoma cells. The biopsy provides the dermatologist with this information. If the mole is benign, removal of additional skin resulting in larger wound and scarring is unnecessary.
What are the pre-operative and post-operative instructions for a biopsy?
No pre-operative precautions are required. Continue your prescribed medications including blood thinners. Remove the bandage before bedtime and wash the site with a mild cleanser such as Cetaphil or soap and water. Change the dressing, cleans the area and apply Aquaphor ointment two times daily to assist with wound healing.
Do not swim in the ocean or pools until the site has completely healed. It is an open wound and inadvertent contaminants in the water may lead to infection. Healing is usually completed in 7-10 days depending on the site.
Shave biopsy vs. Punch biopsy?
The two methods of biopsies most commonly used in dermatologic surgery are shave and punch biopsies. Shave biopsies are performed with a scalpel or blade that removes skin tangentially or on a plane parallel to the skin. They are frequently used to diagnose superficial growths or rashes. Shave biopsies require no stitches and heal similarly to how skin would heel if it was abraded after a fall.
Punch biopsies are performed with a sharp cylindrical tool that one may liken to a thick cookie cutter. Punch biopsies are used when the cause of the rash is deeper in the dermis or an analysis of the deeper portions of the growth is desired. Punch biopsies, due to the depth through the skin, require one or two stitches to close the wound and typically heal well due to the small defect size (2-4mm).
No pre-operative precautions are required. Continue all your prescribed medications including blood thinners. You may remove the bandage in 24 hours and wash the site with soap and water. Change the dressing two times daily and keep moist with Aquaphor healing ointment. In the case of punch biopsies return to the practice in 10-14 days for suture removal.