Welcome back to the journal review. This is the September twenty twenty-six issue of Dermatologic Surgery, and we've got four pieces worth your time this month — a case series on an outpatient bone procedure, a retrospective look at a vitiligo surgery complication, a reconstructive conundrum on the ear, and a ten-year experience with Mohs for nail unit melanoma out of Colombia. Let's get into it.

First up is an original article, though really it reads as a case series and service evaluation, on outpatient superficial bone decortication after Mohs micrographic surgery or excisional surgery for cutaneous malignancies, out of the Royal Victoria Infirmary in Newcastle. The clinical problem here is one every Mohs surgeon has hit — you clear an aggressive tumor, most often on the scalp, and the deep margin overlying clinically uninvolved bone is either microscopically positive or just indeterminate because tissue was missing at that plane. Historically, the answer has been referral to another specialty for burring of the outer cortical table under general anesthesia, which means a delay between tumor removal and definitive bony management, and depending on who's doing it, a risk of burring the wrong site or taking more bone than necessary.

So this group started doing the decortication themselves, same day, under local anesthesia, and built a small prospective case series to test tolerability. Eleven patients over six months — ten after Mohs, one after an incomplete excision — with a mix of eight squamous cell carcinomas, two pleomorphic dermal sarcomas, and one aggressive basal cell carcinoma. Methodologically, this is exactly the right scale and design for the question being asked. They're not trying to prove oncologic efficacy of decortication versus formal craniectomy to the diploic space — they're asking a much narrower, practical question: is this tolerable and safe as an outpatient local-anesthesia procedure? For that, a descriptive case series with a structured mixed-methods questionnaire — Likert pain scale, dichotomous items, open-ended questions — is entirely appropriate and honestly about as much rigor as this kind of pragmatic service-evaluation question needs. Worth noting, because the pain scores weren't normally distributed, they reported medians rather than means, which is the correct instinct — the mean gets dragged around by outliers with skewed data like pain scores clustered at zero, so median is the more honest summary statistic here.

The technique itself is a cross-hatch approach with a pneumatic microdrill and a rosehead bur, run around five thousand RPM, used lightly to create a shallow groove one to two millimeters deep in one plane, then repeated perpendicular to feather down the peaks — all under saline irrigation, with the bone fragments collected and sent for pathology. Local anesthetic goes into the surrounding soft tissue, not the bone itself, since bone has no somatic sensation once periosteum is off.

On results: mean preoperative tumor diameter was about thirty-seven millimeters, mean postoperative defect closer to fifty. Average of just over two Mohs stages. The headline finding is the median pain score during decortication was zero — essentially painless for most patients, described repeatedly as feeling like dental drilling, noisy and vibratory but not uncomfortable. Every single Mohs patient said they'd rather have it done the same day under local than be referred out for a separate general anesthetic procedure. Pathologically, none of the burred bone fragments showed residual tumor in any case. Follow-up was reassuring too — only one soft tissue recurrence, at nine months, successfully managed with further Mohs and referral for deeper burring, and one nodal metastasis that on retrospective review of the original slides likely predated the Mohs surgery rather than reflecting a failure of the decortication itself.

The limitations are the obvious ones for a series this size — eleven patients, no comparator arm, no long-term oncologic outcome data beyond a few years, and this was run as a clinical governance activity rather than a formal trial, so there's no institutional review board oversight to speak of. The authors are appropriately conservative in their framing — this is not proposed as a replacement for deeper bone management when there's frank cortical invasion, just a well-tolerated way to handle the common scenario where the cortex is clinically uninvolved but you want oncologic reassurance at that plane.

Practically, this is a genuinely useful technique read rather than a practice-changing outcomes paper. If you're already doing Mohs on aggressive scalp tumors and routinely hitting this indeterminate-deep-margin scenario, this gives you a reasonable, low-morbidity, same-day option that spares patients a second procedure and a general anesthetic, and the technical details — bur size, RPM, cross-hatch pattern, saline cooling — are specific enough to actually replicate in your own practice.

Next is a retrospective study on the perigraft halo phenomenon after melanocyte-keratinocyte transplantation, or MKTP, for vitiligo, from the National Center of Vitiligo in Riyadh. For those of you who dabble in pigment surgery, MKTP is the noncultured epidermal cell suspension technique used for therapy-resistant stable vitiligo, and perigraft halo is that persistent white rim at the periphery of an otherwise successfully repigmented graft site — a complication that's common but surprisingly under-studied, with reported rates all over the map, roughly six to twenty-five percent in the existing literature.

This was a retrospective cohort of two hundred twenty-three patients, all with photographically documented stable vitiligo who underwent a standardized MKTP protocol, with perigraft halo defined as a white rim present at three months, assessed by a blinded rater. The authors used multivariate logistic regression to hunt for independent risk factors. This is the right tool for the job, and it's worth spending a moment on why. Logistic regression is what you reach for when your outcome is binary — halo present or absent — and you want to know which of several candidate predictors, like body site, lesion type, or patient age, independently move the odds of that outcome once you've accounted for the others. Mathematically, it's modeling the log-odds of the outcome as a linear combination of your predictors, which is why the output comes back as an odds ratio — exponentiate the coefficient and you get how much the odds of halo multiply by for a one-unit change in that variable, holding everything else constant. The reason you don't just run a bunch of separate chi-square tests here is confounding: site, lesion type, and treatment after surgery are all tangled together, and multivariate regression lets you isolate the independent contribution of each.

The results were fairly clean. Overall, about one in five patients — nineteen percent — developed a perigraft halo. On univariate analysis, both lower extremity and foot sites stood out, but once put through the multivariate model, feet remained a strong independent predictor, with roughly a six-fold increase in the odds of halo formation, a finding that was both statistically significant and clinically substantial — this isn't a borderline effect, feet are a genuinely distinct risk category. Interestingly, the lower extremity excluding the feet actually came out as somewhat protective by comparison, which the authors attribute plausibly to lower skin mobility and thicker hair density at that site providing more mechanical stability for graft take, whereas the feet's increased mobility and known poor surgical responsiveness in acral skin — possibly related to lower matrix metalloproteinase expression limiting melanocyte migration to the lesion edge — work against it. None of the postoperative adjuvant treatments they looked at, including topical tacrolimus, excimer laser, or oral psoralen with sunlight, reached statistical significance for reducing halo risk in their data, though the authors are honest that irregular application of topical therapy, which they didn't track, could be masking a real effect.

Limitations are squarely acknowledged — retrospective design, single center, relatively short three-month halo assessment window that may miss later evolution or resolution, and no data on treatment adherence. The authors also did a nice job contextualizing their finding against a broader literature review, noting conflicting reports on whether extending dermabrasion margins or immunosuppressive adjuncts like cyclosporine reduce halo rates, and calling for prospective trials.

For your practice, if you or colleagues offer vitiligo surgery, this is clinically actionable counseling information even if it's not going to change your surgical technique outright — patients being grafted on the feet should be specifically counseled preoperatively that perigraft halo is substantially more likely there, which matters a great deal for expectation-setting given how much this complication affects satisfaction despite otherwise successful repigmentation.

Third, a Reconstructive Conundrum piece — so no methods or statistics here, just a case-based technique discussion — covering reconstruction of a posteroinferior ear and retroauricular-mastoid defect. A ninety-one-year-old man with an infiltrative basal cell carcinoma of the posterior auricle extending into the retroauricular region underwent Mohs, leaving a defect just over five by four centimeters spanning nearly the entire posterior auricle and adjacent retroauricular skin, with periosteal exposure. His stated preference was to avoid suturing the helix down to the retroauricular skin, which would flatten the ear's three-dimensional projection.

The authors walk through why each standard option fails here, which is really the value of this piece. Second intention was out given the periosteal exposure and the size of the deep component — too much contraction risk and infection risk. Primary closure would have obliterated the retroauricular sulcus and risked asymmetry. Full-thickness grafts, usually a workhorse for helix and antihelix defects, were disqualified because of the exposed cartilage and bone at this scale, raising necrosis and retraction risk. The usual donor site for posterior ear defects — adjacent retroauricular skin itself — was unusable because the defect already consumed much of that territory, and extending a flap onto the occipital scalp would have meant recruiting far less lax tissue. A superior cervical advancement flap was considered and rejected as needing an impractically wide flap with excessive donor scarring for an elderly patient they wanted to treat in one session.

Their solution was a preauricular lobulated transposition flap with an inferior pedicle — pulling laxity from the preauricular cheek skin rather than the retroauricular region, transposing it to cover both the posterior auricular surface and the mastoid component in a single flap, anchoring it to the retroauricular perichondrium with absorbable suture to actively reconstruct the sulcus rather than let it flatten. The design borrows from two previously published single-lobe preauricular flap techniques, combined and reoriented with an inferiorly based pedicle to match this particular postero-inferior defect geometry. At two months, they had a good aesthetic and functional result with only mild pincushioning, which they note is an expected and generally self-limited feature of transposition flaps.

The teaching point for your own practice: when the retroauricular donor skin itself is consumed by the defect, don't default straight to a graft or a larger regional flap — the preauricular cheek is a reliable, well-vascularized alternative donor source that lets you reconstruct the sulcus rather than sacrifice it, and it's a good option to keep in your back pocket specifically for combined posterior-auricular-plus-mastoid defects in patients where you want a single-stage repair.

Last, an original article giving ten years of experience with Mohs micrographic surgery for ungual melanoma in situ in a Latin American population, from Bogotá, Colombia. The background gap is real and specific — acral and ungual melanoma make up a much larger share of melanoma in higher Fitzpatrick phototype populations, and yet essentially all the tissue-conserving surgery literature, including the systematic reviews showing no significant difference in recurrence between Mohs, wide local excision, and amputation for nail unit melanoma in situ, comes from cohorts that don't report phototype or ethnicity at all. So this fills a genuine evidentiary blind spot.

This was a retrospective cross-sectional study, thirty-six patients over roughly ten years, all treated with a standardized Mohs protocol — proximal nail fold elevation, dermatoscopically guided margin marking, five-millimeter en bloc excision, paraffin-embedded margin assessment with immunohistochemistry backup when needed, full-thickness skin graft reconstruction once margins were clear. Given the small sample and the fact that most of their variables were categorical rather than continuous, the authors chose multiple correspondence analysis, or MCA, over a regression model to explore the data. This is worth teaching because it's a less commonly encountered technique than logistic regression. MCA is essentially the categorical-data cousin of principal component analysis — instead of finding continuous axes of variance among numeric variables, it finds a low-dimensional map where categories that tend to co-occur across patients — say, "foot location," "plaque morphology," and "male sex" — cluster near each other in the plotted space. It doesn't test a hypothesis or spit out a p-value for a specific predictor the way regression does; it's a purely exploratory, hypothesis-generating tool for surfacing structure in your data when you have too many categorical variables and too few patients to responsibly run a multivariate regression without overfitting. That's exactly the situation here with thirty-six patients and a dozen categorical variables, so the choice is methodologically sound, and the authors are appropriately explicit that this is descriptive and exploratory rather than confirmatory.

On outcomes, this is a strong safety signal: all thirty-six patients achieved complete histologic clearance, and at up to five years of follow-up there were zero recurrences and zero melanoma-related deaths — with a statistically calculated upper bound on that recurrence and mortality rate of around eight percent using the rule-of-three method, which is the standard way to estimate a plausible worst case when you've observed zero events in a finite sample. Most tumors cleared in a single Mohs stage — two-thirds of cases — and final margins came in under six millimeters in the large majority, about eighty-three percent, which is a meaningful point for anyone who has been trained toward wider empiric margins for nail unit melanoma in situ; here, tissue conservation didn't come at the cost of clearance. About a third of patients needed reintervention, with a short turnaround of under two weeks given their three-day paraffin processing pathway.

The MCA itself surfaced three reasonably intuitive clinical-surgical clusters — nodular or scar-like lesions clustering with middle-aged women and hand involvement; plaque or papule morphology clustering with men, foot location, and a higher reintervention rate; and macular lesions clustering with younger patients and fewer reinterventions — though together the first two dimensions only captured about a third of the total variance, so treat these clusters as suggestive pattern-finding rather than a validated predictive model.

Limitations are what you'd expect from a single-center retrospective series of this size — thirty-six patients, no ethnicity data collected despite that being central to the stated rationale for the study, a predominantly lighter-phototype sample within their own cohort which somewhat undercuts the framing, and the descriptive nature of the MCA findings, which the authors themselves flag as needing multicentric validation.

The bottom line for practice: this adds reassuring, phototype-diverse, real-world data that Mohs for ungual melanoma in situ can achieve excellent long-term local control with margins meaningfully narrower than empiric wide excision would give you, which is useful confirmatory evidence if you're already doing this — but the subgroup clustering is interesting hypothesis-generating material, not something to act on yet in terms of tailoring margins or technique by lesion morphology or anatomic site.

That wraps this month's roundup — a well-tolerated new outpatient bone technique worth adding to your armamentarium, a practical risk-counseling data point for vitiligo surgery patients getting grafted on the feet, a clever preauricular flap solution for a genuinely tricky combined ear defect, and further confirmation that conservative, margin-controlled surgery holds up for ungual melanoma in situ across diverse populations. Thanks for listening, and I'll see you next month.