Photos and Biopsy Marking Are Not Optional
When PA Buchi Neita and co-host PA Jennifer Connor asked their guest, Dr. Riley McLean, how she wants biopsies documented, she called it her "ultimate soapbox." Because she doesn't do general dermatology, nearly all her referrals come from colleagues — and high-quality photos make the surgical day start and finish successfully.
Dr. McLean cited studies showing that patients misidentify their own biopsy site roughly 6–10% to 30% of the time. Even more striking, she noted that in the same study, surgeons themselves misidentified the location about 6% of the time when working from a named location without a photo. Her point: humans make errors, so stack as much evidence as you can against them.
Her practical recipe is two photos. One from farther away to establish location—for a forearm lesion, include the elbow and wrist; for the scalp, include both ears and the nose. Then one closer up to capture nearby landmarks like a nevus. For marking, she prefers four dots around the lesion or coloring in the surface of the target (for example, the surface of a basal cell) rather than leaving purple pen scattered across the face. She also warned that some EMRs auto-populate a location based on where you click, and those are often wrong — the photo is the most reliable counterbalance.
Biopsy Technique: Think Suspicion, Then Intention
Dr. McLean frames every biopsy around two questions: what am I suspicious for, and what is my goal? For anything melanocytic, she called partial biopsies "awful" — you never know if you'll catch the worst part, and one half can read as moderately atypical while the other half is melanoma. Her advice is to do a broad shave to capture the whole pigmented lesion, and if you suspect invasive melanoma, don’t transect it — or, if depth makes transection inevitable, biopsy deep enough to still guide the sentinel node decision. As she put it, for suspected melanoma she is "swinging for the fences" and will deal with the scar later.
For non-melanoma skin cancers, the priority flips to preserving normal skin. Get enough to diagnose, but don't take an 8–9 mm sample of a 5 mm basal cell, because the surgeon then has to go around all that extra normal tissue. Neita noted she'd never considered that the Mohs surgeon has to work around the entire biopsy site to ensure clear margins.
Dr. McLean added that intention also matters. For patients with "surgical fatigue" — she flagged that anyone getting more than about four skin cancers a year develops it quickly — a scoop that clears the lesion may save another visit. And for cosmetically sensitive patients, especially women's faces, she reaches for punch biopsies more often, because closing the sides shrinks the overall footprint and therefore what the surgeon later has to remove.
Deciding on Mohs: The AUC App and the Whole Patient
Dr. McLean still uses the Mohs Appropriate Use Criteria (AUC) app several times a week. Her rough rule of thumb: head lesions generally go to Mohs, while trunk lesions require thinking about size and aggressive features. Certain pathology words — sarcomatoid, poorly differentiated, or rare tumors she has to look up — don't just point toward Mohs but change how quickly she moves. She wants to know about those in advance.
She also flagged a detail that surprised the hosts: some topical field agents (including a formulation with peanut oil) can cross-react with nut allergies, which can push a patient toward Mohs when field therapy is off the table. She was also clear that meeting AUC criteria doesn't mandate surgery. For very elderly patients, those with dementia, limited life expectancy, or poor healing, she'll consider alternatives — intralesional 5-FU or methotrexate, PDT, and growing (though not yet routine) evidence for imiquimod in superficial and nodular BCCs.
Neita shared her own approach to frail patients: "you're in charge now, not me." Dr. McLean echoed the sentiment with a line she borrowed from a fellow applicant — "this is your party, I'm your DJ." Her broader message: find a Mohs surgeon who treats the patient as a whole picture, not just a tumor.
Beyond BCC and SCC — and Field Therapy Timing
Basal cell and squamous cell carcinomas remain the bread and butter, but Dr. McLean discussed several others. Her institution uses "slow Mohs" (overnight processing with immunostains) for melanoma in situ and for non-lymph-node-qualifying invasive melanomas in sun-exposed areas, noting the on-face margin checking correlates with better prognosis. She reminded listeners that standard wide local excision breadloafs tissue and examines only a small fraction of the margin, whereas en-face margins look at the entire edge. Once a melanoma is thicker than 0.8 mm, or invasive and ulcerated, the sentinel node conversation usually sends the patient to surgical oncology instead.
She highlighted DFSP, which can recur in up to 50% of cases with general or oncologic surgery but drops to about 8% with Mohs, and named AFX and pleomorphic dermal sarcoma as personal clinical interests. Merkel cell, by contrast, she called a hot topic — Mohs handles local margins well, but the high metastatic risk usually means a solid excision and fast referral to radiation, with surgical oncology quarterbacking most cases.
On field cancerization, Dr. McLean loves it as neoadjuvant or adjuvant therapy but wants inflammation settled before she operates — no topical treatment in the surgical area for at least three to four weeks beforehand, and she prefers longer. Afterward, patients can often restart within about a week. Her personal favorite field therapy is compounded 5-fluorouracil with calcipotriene, with PDT as a strong alternative.
Counseling and Consults: Set the Expectation
Dr. McLean's top counseling tip was experiential: reach out to your Mohs surgeon and ask to work a half day, so you understand the flow and can echo their exact spiel. Every office differs — hers keeps patients in the same room rather than a waiting area, asks guests to step out during the procedure, and uses wave scheduling. Telling patients to plan for two to four hours, much of it waiting, sets a realistic frame.
She stressed being honest about scarring — patients sometimes arrive convinced they were promised none. The truthful version is that the best possible scar comes from Mohs, in hands doing thousands of these a year, but there will be a scar. For anxious patients or those with unrealistic expectations, she encouraged suggesting a consult first, which also lets the surgeon flag when a large tumor, a rare tumor, or a patient who needs extra handling might warrant outside plastic surgery closure.