Recurrence Rate of Small Melanoma In Situ on Low-Risk Sites Excised With 5-mm Excisional Margin.

Importance: The incidence of melanoma in situ (MIS) has increased significantly over the past decades, and traditional guidelines for treatment of MIS have been excision with a 5-mm clinical margin; however, current Australian and other guidelines now recommend 5- to 10-mm margins. This changed recommendation was largely driven by the outcomes of studies using Mohs micrographic surgery, and recent studies using Mohs micrographic surgery are advocating for even wider excisions up to 18 mm for clearance. Objective: To assess the rate of recurrence of MIS excised with a 5-mm margin. Design, Setting, and Participants: This case series studied all MIS lesions from a single private dermatology clinic between January 1, 2011, and November 30, 2018. The criteria for inclusion were a documented 5-mm excisional margin on operation report and more than 5 years of site-specific follow-up after wide local excision. Lesions were excluded if the excisional margin was more than 5 mm or undocumented, there was less than 5 years of follow-up, or they required more than 1 wide local excision. Data analysis was performed January 30 to February 25, 2024. Intervention: Wide local excision with 5-mm margin. Results: A total of 351 MISs were identified from 292 patients (mean [SD] age, 60.3 [11.8] years; 162 females [55.5%]). Superficial spreading melanoma was the most common subtype diagnosed (177 lesions [50.4%]), followed by lentigo maligna (107 lesions [30.5%]) and lentiginous MIS (67 lesions [19.1%]). The trunk was the most common location of lesions (168 lesions [47.9%]), followed by upper limb (96 lesions [27.4%]) and lower limb (59 lesions [16.8%]). Scalp was the least common location (2 lesions [0.6%]). Most of the lesions were small, with 274 lesions (78.1%) having a length less than 10 mm and 312 lesions (88.9%) having a width less than 10 mm. A total of 348 lesions (99.1%) did not have clinical recurrence after excision with a 5-mm clinical margin following then current guidelines. A total of 3 lesions (0.9%) experienced local recurrence with no metastatic spread. Conclusions and Relevance: This case series found that excision with a 5-mm margin for MIS of smaller size (<10 mm) on low-risk body sites had a low rate of recurrence. Conservative 5-mm excisional margin is likely to be suitable for small MIS on lower-risk body sites.

Growing Adoption of Immunohistochemistry by Mohs Micrographic Surgeons: A National Medicare Trend Analysis.

BACKGROUND: Immunohistochemical (IHC) staining can be used alongside Mohs micrographic surgery to aid in margin assessment of subtle tumors, yet existing estimates of IHC utilization have primarily relied on survey or older data that lacks stratification. OBJECTIVE: To characterize national IHC utilization trends by Mohs surgeons, stratifying by surgeon characteristics and modeling future adoption. METHODS: Longitudinal analysis of 2014 to 2021 Medicare Public Use Files. RESULTS: In 2021, 158 of 2,058 Mohs surgeons (7.7%) used IHC as compared with 4.0% in 2014 (average annual growth rate [AAGR] +3.6%). Adoption change was highest in the Northeast (AAGR +19.9%), whereas volume growth was greatest in the West (AAGR +25.2%). Multivariable regression revealed significantly greater utilization propensity among Mohs surgeons in academics (adjusted odds ratio [aOR] 3.36), American College of Mohs Surgery (ACMS) members (aOR 2.12), and Micrographic Dermatologic Surgery (MDS)-certified surgeons (aOR 1.66). CONCLUSION: Mohs surgeons are steadily incorporating IHC into practice across all regions, with volume growth driven by higher adoption rates. Greater utilization among ACMS members, recipients of MDS certification, and those in academics suggests value of formalized training in enhancing comfort. Additional educational opportunities at conferences may aid in recognition of value and help identify solutions to address integration challenges.

A Systematic Review of the Epidemiology, Clinical Characteristics, Treatment, and Outcomes for Desmoplastic Trichoepithelioma: Underscoring Mohs Micrographic Surgery in Management.

BACKGROUND: Desmoplastic trichoepithelioma (DTE) is an uncommon benign adnexal tumor that histologically may mimic malignant tumors including basal cell carcinoma and microcystic adnexal carcinoma. OBJECTIVE: To present a systematic review of the epidemiology, clinical characteristics, treatment, and outcome data on DTEs, with emphasis on comparing Mohs micrographic surgery (MMS) with other treatments. METHODS: Using the OVID platform, MEDLINE and Embase were searched from inception for studies providing original data on DTEs. RESULTS: A total of 338 cases of DTE from 61 articles were included. No recurrence/persistence (0%) was reported following MMS ( n = 24, mean follow-up of 41.9 months), 13.1% with standard excision ( n = 38, mean follow-up 16.9 months), and 2.1% for electrosurgery/cautery ( n = 49, follow-up 3-72 months). 100% recurrence/persistence for imiquimod ( n = 2) and liquid nitrogen ( n = 4) were identified. In patients who underwent biopsy only, there was a 12.5% recurrence/persistence ( n = 32, mean follow-up 16.5 months). Overall, duration of follow-up varied from 2 months to 6 years for the various management strategies. CONCLUSION: Data are limited regarding DTE outcomes. In this review, surgical modalities, specifically MMS, had the lowest rates of recurrence/persistence compared with other options. Given that most lesions are found on cosmetically sensitive locations, MMS seems to be the optimal management strategy for actively managing DTEs.

Age group-specific changes in keratinocyte cancer treatment rates in Australia, 2012-2021: a retrospective cohort study based on MBS claims data.

OBJECTIVES: To examine recent changes in the numbers of Medicare-subsidised keratinocyte cancer excisions, particularly for younger people exposed to primary prevention campaigns since the early 1980s. STUDY DESIGN: Retrospective cohort study; analysis of administrative data. SETTING, PARTICIPANTS: Analysis of Medicare Benefits Schedule (MBS) claims data for procedures related to the diagnosis and treatment of keratinocyte cancer in Australia, 2012-2021. MAIN OUTCOME MEASURES: Age-standardised rates for MBS-subsidised claims for first surgical squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) excisions, Mohs surgery, surgical excisions of benign lesions, skin biopsies, and cryotherapy or serial curettage of premalignant and malignant lesions, overall, and by sex, state/territory, and age group; average annual percentage change in rate for time intervals determined by joinpoint regression. RESULTS: In men, the age-standardised rate of BCC/SCC excisions increased by 1.9% (95% confidence interval [CI], 1.4-2.4%) per year during 2012-2019 (from 2931 to 3371 per 100 000 men) and then declined by 3.8% (95% CI, 0.5-7.0%) per year during 2019-2021 (to 3152 per 100 000). In women, the age-standardised rate increased by 2.2% (95% CI, 1.7-2.8%) per year during 2012-2019 (from 1798 to 2093 per 100 000 women); the decline to 1967 excisions per 100 000 women in 2021 was not statistically significant. BCC/SCC excision rates declined for men under 55 years of age (by 1.0-3.4% per year) and women under 45 years of age (by 1.7-2.3% per year). Age-standardised biopsy rates increased during 2012-2021 in all age groups (by 2.8-6.9% per year). CONCLUSIONS: Rates of MBS-subsidised treatment for keratinocyte cancers increased during 2012-2019, but BCC/SCC treatment rates declined among younger Australians, who have probably been exposed to less sunlight than earlier generations because of public health interventions and population-wide lifestyle changes related to technology use.

Prognostic Analysis of Patients With Extramammary Paget Disease Treated With Conservative Excision.

BACKGROUND: Extramammary Paget disease (EMPD) is a malignant skin tumor with a relatively good prognosis. The standard treatment is wide local resection or Mohs micrographic surgery. However, conservative excision may be a better option when radical wide local excision is difficult to perform due to the patients' mental or physical condition. There have been no studies on the prognosis of patients with EMPD who underwent conservative excision. OBJECTIVE: To compare the prognosis of conservative excision cases to wide excision cases of EMPD. MATERIALS AND METHODS: The authors retrospectively analyzed the clinical data of 69 cases of EMPD without metastases to lymph nodes or organs (11 cases treated with conservative excision, 58 cases treated with wide local excision) who underwent resection of the primary tumor from 2002 to 2022 in the Department of Dermatology at Hokkaido University Hospital. RESULTS: The log-rank test showed no significant differences in overall survival or metastasis-free survival between the wide excision group and the conservative excision group, although conservative surgery was often chosen in elderly patients or patients with lower performance status. CONCLUSION: This study suggests that conservative surgery should be considered as a treatment option for EMPD.

Morbidity and Mortality of Melanoma on the Trunk and Extremities Treated With Mohs Surgery Versus Wide Excision: A Systematic Review.

BACKGROUND: Recommendations for the approved use of Mohs surgery for cutaneous melanoma on the trunk and extremities remain uncertain. OBJECTIVE: To compare survival and recurrence between patients treated with Mohs surgery versus wide excision for melanoma on the trunk and extremities. METHODS: The databases Medline, Embase, Web of Science, CENTRAL, and EMCare were searched from inception on January 11, 2021. Contemporary comparisons were included exclusively. Meta-analysis was conducted using generic inverse variance and a fixed effects model. RESULTS: Four studies were eligible for inclusion. The study population (n = 279,556) was 52.1% men and 97.2% White. There were no observed differences in 5-year overall survival (hazard ratio 0.98, 95% confidence interval 0.90-1.07, I2 = 0%), disease-free survival (HR 0.89, 95% CI 0.12-6.47, I2 = 0), or local recurrence among patients treated with Mohs surgery relative to wide excision. Quality of the evidence was very low. CONCLUSION: This systematic review found survival and local recurrence were comparable among patients treated with Mohs surgery or wide excision for melanoma on the trunk and extremities. Future prospective contemporary studies with more diverse representation that report surgical complications and costs may facilitate more definitive recommendations.

Rates of Upstaging, Between Diagnosis and Surgery, and Clinical Management of Metastatic Cutaneous Squamous Cell Carcinoma: A Case-Control Study.

BACKGROUND: Cutaneous squamous cell carcinomas (cSCC) have upstage rates of approximately 10.3% to 11.1%. Data are currently limited on the rate of upstaging for metastatic cSCC. OBJECTIVE: The aim of this study was to determine the rates of upstaging, between diagnosis and surgery, and differences in management for metastatic and non-metastatic high-risk cSCC. MATERIALS AND METHODS: This was a retrospective, case-control, single institution, multi-center study. Univariate analysis was used. RESULTS: Sixty-eight subjects (34 metastatic & 34 non-metastatic) with 69 tumors were included. The overall rate of upstaging was 46.4%. The most common reasons for upstage were undocumented tumor size and under-diagnosis of poor differentiation. There were no differences in rates of upstaging. Preoperative imaging was performed in 43.6% of wide local excisions (WLE) versus 3.3% of Mohs micrographic surgery (MMS; p < .001). The median days from surgery to sentinel lymph node biopsy (SLNB), or nodal dissection was shorter for WLE versus MMS (0 vs 221 days, p < .001). CONCLUSION: Improved clinical documentation, including documenting tumor size, and the identification of pathologic risk factors, including poor differentiation and depth of invasion, are needed for proper staging. Preoperative imaging and discussion of SLNB may be beneficial for high-risk T2b and T3 tumors.

Treatment of Cutaneous Melanoma of the Head and Neck With Wide Local Excision Versus Mohs.

OBJECTIVES: Determine if Mohs micrographic surgery (MMS) is associated with improved overall survival compared to wide local excision (WLE) when treating cutaneous melanoma of the head and neck (CMHN) and to report the proportion of patients treated with MMS versus WLE who also underwent sentinel lymph node biopsy (SLNB). METHODS: Retrospective cohort study of the National Cancer Database (NCDB) analyzing the overall survival of patients diagnosed with T1 to T4 CMHN between 2004 and 2016 who were treated with either WLE or MMS. RESULTS: On multivariable analysis, treatment with WLE versus MMS was not significantly associated with overall survival (HR, 1.094; 95% CI, 0.997-1.201). On multivariable analysis, lower Charlson-Deyo score (HR, 0.489; 95% CI, 0.427-0.560), negative margins (HR, 0.754; 95% CI, 0.705-0.807), and N0 classification (HR 0.698; 95% CI, 0.668-0.730) were associated with improved overall survival. Seventy-seven percent of patients treated with MMS did not undergo SLNB, while 45% of patients treated with WLE did not undergo SLNB (P < .001). CONCLUSIONS: No difference in overall survival between MMS and WLE when treating CMHN. Patients treated with MMS were significantly less likely to undergo SLNB, suggesting an opportunity for enhancement of multidisciplinary care. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:2490-2496, 2021.

Evaluation of Public Interest in Mohs Surgery and Other Elective Surgical Procedures During the COVID-19 Pandemic.

BACKGROUND: The reallocation of health care resources to focus on the acute care needs of COVID-19 patients leads to a delay and deferral of outpatient surgical procedures such as Mohs surgery. OBJECTIVE: Planning for the resumption of regular outpatient surgical care and preparing for future surges in COVID-19 cases requires identifying surrogate markers of health care demand. MATERIALS AND METHODS: United States national and state-based Google search data for "Mohs surgery" and other common elective surgical and cosmetic procedures were evaluated. These were compared with national and state-wide COVID-19 case number and death data from the Johns Hopkins University. Pearson correlation coefficients were generated to assess the association between COVID-19 cases and deaths with Google search trends. RESULTS: Search volume for "Mohs surgery" and other elective surgical and cosmetic procedures significantly decreased as the number of new deaths from COVID-19 increased. Statistically significant inverse correlation was noted between "Mohs surgery" search volume and new COVID-19 deaths on a national and state-based level. CONCLUSION: Search metric analysis may be used as part of a big data model to help predict health care demand during the reopening phase of the COVID-19 pandemic.

Employment and Migration Patterns of Recent Micrographic Surgery and Dermatologic Oncology Fellowship Graduates.

BACKGROUND: There is currently an uneven distribution of the Mohs surgery workforce, with a dearth in nonurban areas. The relationship between training and employment locations of Mohs surgeons has not been studied. OBJECTIVE: To analyze the employment location of recent micrographic surgery and dermatologic oncology (MSDO) graduates in reference to residency and fellowship locations. MATERIALS AND METHODS: Data collection of training and practice locations of 421 MSDO fellowship graduates from 2012 to 2017. RESULTS: Thirty-two percent (n = 136) and 53% (n = 225) of MSDO fellowship graduates' first employment locations were located within 10 and 100 miles of either their residency or fellowship locations. Ninety-six percent of graduates were employed in a metropolitan location. Female graduates worked closer to training sites than male graduates, with 62% (n = 124) versus 46% (n = 102) working within 100 miles of either training site. Analysis by fellowship census region showed that graduates clustered around training sites in all regions, with 45% to 60% of graduates working within 100 miles of either training site. CONCLUSION: The majority of graduates chose to work in a metropolitan area. Training location strongly predicts employment location. More than 45% of graduates in any region worked within 100 miles of their residency or fellowship site, and a sizeable portion worked within 10 miles.

Malignant Cutaneous Adnexal Tumors and Role of SLNB.

BACKGROUND: Malignant cutaneous adnexal tumors (MCATs) are rare and their natural history is poorly understood. Available literature indicates aggressive behavior with a significant risk of metastasis. STUDY DESIGN: Retrospective review of our institutional surgical oncology databases was performed for patients diagnosed with MCATs (2001-2020). We hypothesized that most patients have a low risk of lymph node involvement, recurrence, and death. Kaplan-Meier statistical analysis was used to assess risk of recurrence and 5-year survival. RESULTS: We identified 41 patients diagnosed with MCATs (median age 59 years, 68% were men). Most patients had long-standing cutaneous lesions (median 24 months) and no palpable adenopathy. Most patients had stage I or II disease (98%). Primary tumors were treated with wide local excision (n = 28 [68%]), Mohs surgery (n = 5 [12%]), or amputation (n = 8 [19%]). Of 25 patients who underwent SLNB (61%), 1 had lymphatic metastasis. These include apocrine carcinoma (1 of 3), digital papillary adenocarcinoma (0 of 8), porocarcinoma (0 of 4), and additional MCAT sub-types (0 of 10). Three patients (7%) had disease recurrence at a median interval of 3.6 years (interquartile range 1.5 to 4.4 years). Five patients (12%) died at a median interval of 7 years (interquartile range 6.7 to 9.2 years), but only 1 patient was known to have succumbed to MCAT. Overall 5-year survival rate was 96% (95% CI, 75% to 99%). CONCLUSIONS: Despite the historical impression that MCATs have a high metastatic potential, most patients have low recurrence rates and excellent 5-year survival rates. Lymphatic disease identified after SLNB in early-stage tumors is rare and the value of this staging procedure in MCAT remains unclear.

Characteristics of Superficial Basal Cell Carcinomas Containing More Aggressive Subtypes on Final Histopathologic Diagnosis.

BACKGROUND: The prognosis and treatment of basal cell carcinoma (BCC) are largely dependent on tumor subtype, which is typically determined by punch or shave biopsy. Data regarding concordance between BCC subtype on initial biopsy and final histopathology for Mohs micrographic surgery (MMS) or excision with frozen sections (EFS) are limited. OBJECTIVES: To determine the concordance between initial biopsy and final MMS or EFS subtyping of BCC. We aim to investigate the incidence and clinical characteristics of lesions initially diagnosed as superficial BCC (sBCC) that are later found to have a nodular, micronodular, or infiltrative component. METHODS: We conducted a retrospective review of all MMS or EFS cases performed at a single academic center from August 1, 2015 to August 31, 2017. Inclusion criteria were a biopsy-proven diagnosis of sBCC and presence of residual tumor following stage I of MMS or EFS. Fisher’s exact test was used to evaluate significance of clinical characteristics and outcomes associated with the presence of a nodular, micronodular, or infiltrative BCC component. RESULTS: A total of 164 MMS or EFS cases had an initial biopsy showing sBCC. Of these, 117 had residual BCC on stage I, and 43 (37%) were found to have a nodular, micronodular, or infiltrative component. Significant predictors of reclassified BCC subtype included age over 60 years (P=0.006) and location on the head or neck (P=0.043). Reclassified lesions required significantly more stages of MMS to clear (P=0.036). Shave biopsy was used to diagnose 114 (98%) of the included cases. CONCLUSIONS: Over one third of shave biopsies that initially diagnosed sBCC failed to detect a nodular, micronodular, or infiltrative component. Management of biopsy-proven sBCC should take into account the possible presence of an undiagnosed deeper tumor component with appropriate margin-assessment treatment modalities when clinically indicated. J Drugs Dermatol. 2021;20(3):283-288. doi:10.36849/JDD.5383.

Diagnostic Biopsy via In-Office Frozen Sections for Clinical Nonmelanoma Skin Cancer.

BACKGROUND: Treatment of nonmelanoma skin cancer (NMSC) by Mohs surgery has traditionally relied on previous pathologic evaluation of paraffin-embedded tissue. Tissue processing by frozen sections allows for expedited diagnosis and treatment; however, data on its accuracy are limited. OBJECTIVE: To measure the accuracy and outcomes of biopsy via frozen sections for clinical NMSC. METHODS: Biopsies of clinical NMSCs processed via frozen sections with in-office diagnosis rendered by one Mohs surgeon were retrospectively reviewed by one board-certified dermatopathologist. Discordant diagnoses were re-read in blinded fashion by both physicians. If still discordant, final diagnosis was determined by consensus discussion. Inter-rater reliability was calculated using Cohen's kappa statistic. RESULTS: Two hundred ninety-seven lesions from 208 patients were included. Correlation between in-office and final diagnosis was 0.876 indicating "almost perfect" concordance. Sensitivity and specificity of in-office diagnosis for detecting malignancy were 98.1% and 94.4%. Seven cases (2.0%) had a clinically relevant change in final diagnosis, but appropriate treatment had been rendered. Two benign lesions (0.7%) initially diagnosed as malignant underwent excision. CONCLUSION: In-office biopsy via frozen sections is highly accurate in confirming NMSC. This practice may speed diagnosis and treatment thus improving outcomes and patient satisfaction.