Mohs micrographic surgery challenges and new technologies to optimize care of cutaneous malignancies of the ear.

Cutaneous malignancies affecting the ear, exacerbated by extensive ultraviolet (UV) exposure, pose intricate challenges owing to the organ's complex anatomy. This article investigates how the anatomy contributes to late-stage diagnoses and ensuing complexities in surgical interventions. Mohs Micrographic Surgery (MMS), acknowledged as the gold standard for treating most cutaneous malignancies of the ear, ensures superior margin control and cure rates. However, the ear's intricacy necessitates careful consideration of tissue availability and aesthetic outcomes. The manuscript explores new technologies like Reflectance Confocal Microscopy (RCM), Optical Coherence Tomography (OCT), High-Frequency, High-Resolution Ultrasound (HFHRUS), and Raman spectroscopy (RS). These technologies hold the promise of enhancing diagnostic accuracy and providing real-time visualization of excised tissue, thereby improving tumor margin assessments. Dermoscopy continues to be a valuable non-invasive tool for identifying malignant lesions. Staining methods in Mohs surgery are discussed, emphasizing hematoxylin and eosin (H&E) as the gold standard for evaluating tumor margins. Toluidine blue is explored for potential applications in assessing basal cell carcinomas (BCC), and immunohistochemical staining is considered for detecting proteins associated with specific malignancies. As MMS and imaging technologies advance, a thorough evaluation of their practicality, cost-effectiveness, and benefits becomes essential for enhancing surgical outcomes and patient care. The potential synergy of artificial intelligence with these innovations holds promise in revolutionizing tumor detection and improving the efficacy of cutaneous malignancy treatments.

3D bioprinting: a review and potential applications for Mohs micrographic surgery.

Mohs Micrographic Surgery (MMS) is effective for treating common cutaneous malignancies, but complex repairs may often present challenges for reconstruction. This paper explores the potential of three-dimensional (3D) bioprinting in MMS, offering superior outcomes compared to traditional methods. 3D printing technologies show promise in advancing skin regeneration and refining surgical techniques in dermatologic surgery. A PubMed search was conducted using the following keywords: "Three-dimensional bioprinting" OR "3-D printing" AND "Mohs" OR "Mohs surgery" OR "Surgery." Peer-reviewed English articles discussing medical applications of 3D bioprinting were included, while non-peer-reviewed and non-English articles were excluded. Patients using 3D MMS models had lower anxiety scores (3.00 to 1.7, p < 0.0001) and higher knowledge assessment scores (5.59 or 93.25% correct responses), indicating better understanding of their procedure. Surgical residents using 3D models demonstrated improved proficiency in flap reconstructions (p = 0.002) and knowledge assessment (p = 0.001). Additionally, 3D printing offers personalized patient care through tailored surgical guides and anatomical models, reducing intraoperative time while enhancing surgical. Concurrently, efforts in tissue engineering and regenerative medicine are being explored as potential alternatives to address organ donor shortages, eliminating autografting needs. However, challenges like limited training and technological constraints persist. Integrating optical coherence tomography with 3D bioprinting may expedite grafting, but challenges remain in pre-printing grafts for complex cases. Regulatory and ethical considerations are paramount for patient safety, and further research is needed to understand long-term effects and cost-effectiveness. While promising, significant advancements are necessary for full utilization in MMS.

A Pearl for Pretibial and Forearm Repair Following Mohs Micrographic Surgery.

Wound repair of the pretibial and forearm regions presents a challenge during dermatologic surgery as these areas are under significant tension and exhibit increased skin fragility. Various methodologies have been proposed for the closure and repair of such wounds, however, the use of the bilayered suture technique may be simpler and more effective than other techniques such as the pinch stitch, pully stitch, slip-knot stitch, pulley set-back dermal suture, horizontal mattress suture, pully stitch, and tandem pulley stitch. Our objective was to describe a novel method for the repair of pretibial and forearm wounds following Mohs micrographic surgery utilizing bilayered closure followed by tissue adhesive application.  J Drugs Dermatol. 2024;23(5):380.     doi:10.36849/JDD.7139  .

Results of Mohs' Micrographic Surgery of Periocular Basal Cell Carcinoma: The Swedish Experience.

The Department of Ophthalmology, Sahlgrenska University Hospital, has until recently been the only eye clinic in the Nordic countries to perform Mohs' micrographic surgery of basal cell carcinoma. This has led to the practice of only the most complicated basal cell carcinomas being operated on with this technique. The purpose of this study was to present the results of these surgeries in patients with at least 5 years of follow-up. A retrospective study of all patients operated upon in 2010-2015 was performed. Data were gathered from their medical charts. Primary outcome was recurrence of basal cell carcinoma. One-hundred and sixty-seven patients were operated on. Mohs' micrographic surgery was used for tumours that were judged as highly aggressive on preoperative biopsy, had ill-defined borders, had recurred after previous surgery, or a combination of these factors. Nine recurrences (5.4% of all radical Mohs' micrographic surgeries) were diagnosed after a mean postoperative time of 37 months (4-84 months). Interestingly, all of these 9 recurrences after Mohs' micrographic surgery were in patients who had such surgery because of a recurrent basal cell carcinoma to start with. Good results can be achieved when operating on the most complicated periocular basal cell carcinomas with Mohs' micrographic surgery but special care has to be taken to ensure radical borders when operating on recurring basal cell carcinomas.

Using optical coherence tomography to optimize Mohs micrographic surgery.

Mohs micrographic surgery (MMS) is considered the gold standard for treating high-risk cutaneous basal cell carcinoma (BCC), but is expensive, time-consuming, and can be unpredictable as to how many stages will be required or how large the final lesion and corresponding surgical defect will be. This study is meant to investigate whether optical coherence tomography (OCT), a highly researched modality in dermatology, can be used preoperatively to map out the borders of BCC, resulting in fewer stages of MMS or a smaller final defect. In this prospective study, 22 patients with BCC undergoing surgical excision were enrolled at a single institution. All patients had previously received a diagnostic biopsy providing confirmation of BCC and had been referred to our center for excision with MMS. Immediately prior to performing MMS, OCT was used to map the borders of the lesion. MMS then proceeded according to standard protocol. OCT images were compared to histopathology for agreement. Histopathologic analysis of 7 of 22 MMS specimens (32%) revealed a total absence of BCC, indicating resolution of BCC after previous diagnostic biopsy. This outcome was correctly predicted by OCT imaging in 6 of 7 cases (86%). Nine tumors (9/22, 41%) had true BCC and required a single MMS stage, which was successfully predicted by pre-operative OCT analysis in 7 of 9 cases (78%). The final six tumors (27%) had true BCC and required two MMS stages for complete excision; preoperative OCT successfully predicted the need for a second stage in five cases (5/6, 83.3%). Overall, OCT diagnosed BCC with 95.5% accuracy (Cohen's kappa, κ = 0.89 (p-value = < 0.01) in the center of the lesion. Following a diagnostic biopsy, OCT can be used to verify the existence or absence of residual basal cell carcinoma. When residual tumor is present that requires excision with MMS, OCT can be used to predict tumor borders, optimize surgery and minimize the need for additional surgical stages.

Double Immunohistochemical Labelling of PRAME and Melan A in Slow Mohs Biopsy Margin Assessment of Lentigo Maligna and Lentigo Maligna Melanoma.

Introduction: Lentigo maligna (LM) and lentigo maligna melanoma (LMM) predominantly affect the head and neck areas in elderly patients, presenting as challenging ill-defined pigmented lesions with indistinct borders. Surgical margin determination for complete removal remains intricate due to these characteristics. Morphological examination of surgical margins is the key form of determining successful treatment in LM/LMM and underpin the greater margin control provided through the Slow Mohs micrographic surgery (SMMS) approach. Recent assessments have explored the use of immunohistochemistry (IHC) markers, such as Preferentially Expressed Antigen in Melanoma (PRAME), to aid in LM/LMM and margin evaluation, leveraging the selectivity of PRAME labelling in malignant melanocytic neoplasms. Methods: A Novel double-labelling (DL) method incorporating both PRAME and MelanA IHC was employed to further maximise the clinical applicability of PRAME in the assessment of LM/LMM in SMMS biopsies. The evaluation involved 51 samples, comparing the results of the novel DL with respective single-labelling (SL) IHC slides. Results: The findings demonstrated a significant agreement of 96.1% between the DL method and SL slides across the tested samples. The benchmark PRAME SL exhibited a sensitivity of 91.3% in the SMMS specimens and 67.9% in histologically confirmed positive margins. Discussion: This study highlights the utility of PRAME IHC and by extension PRAME DL as an adjunctive tool in the assessment of melanocytic tumours within staged excision margins in SMMS samples.

Removal of Incidental Skin Cancer During Mohs Micrographic Surgery Indicated for a Different Primary Tumor.

BACKGROUND: Mohs surgery is a tissue-sparing, microscopically controlled procedure used to treat biopsy-proven skin cancers. Because Mohs surgery allows for examination of the complete margin of each tissue layer removed, separate cancers can be treated concomitantly when identified. As early detection of skin cancer is beneficial for reducing morbidity, incidental tumors discovered during Mohs surgery are of significant interest. OBJECTIVE: Our objective was to determine the prevalence and characteristics of incidental skin cancers found during Mohs surgery. METHODS: A retrospective chart review of cases seen at University of California, San Diego, from 2014 to 2021 was performed. RESULTS: Of 13,464 Mohs surgery cases, 4.53% ( n = 610) had incidental skin cancers found during removal of the initially identified tumor. Of the 610 cases, 88.4% ( n = 539) had basal cell carcinoma as the primary tumor and either squamous cell carcinoma (SCC) or SCC in situ as the incidental tumor. About 7.87% ( n = 48) had SCC as the primary tumor and basal cell carcinoma as the incidental tumor. All tumors were removed with clear margins and without significant complications. CONCLUSION: Diagnosis of incidental tumors during Mohs surgery enables early detection of skin cancer and circumvents the need for additional surgery, likely resulting in decreased morbidity and improved cost-effectiveness.

Excision margins for melanoma in situ on the head and neck-A single-center 10-year retrospective review of treatment with Mohs micrographic surgery.

BACKGROUND: Although current guidelines recommend a 5 mm surgical margin for the excision of melanoma in situ (MIS), increasing evidence has shown this may be suboptimal to achieve tumor clearance. OBJECTIVE: To evaluate margins required for optimal cure rates with excision of MIS on the head and neck and investigate tumor and/or patient factors in those requiring >5 mm margins to achieve tumor clearance. METHODS: A retrospective chart review was performed on 846 (807 primary and 39 recurrent) MIS cases on the head and neck treated in the authors' dermatologic surgery department over a 126-month (10.5 year) period. RESULTS: Sixty-two percent were cleared with 5 mm margins. A total of 15 mm margins were required to achieve a 97% clearance rate. Difference in clearance rate between margin thresholds was significant (P < .001). Tumor location on the cheek and larger preoperative size correlated with requiring >5 mm margins to achieve tumor clearance (P = .006 and P = .001, respectively). LIMITATIONS: This is a single-center retrospective study which relies on accurate documentation of clinical data. CONCLUSION: This study demonstrates that MIS on the head and neck often requires margins >5 mm margins to achieve tumor clearance. When Mohs micrographic surgery is not possible, excision margins of ≥10 mm are likely necessary for head and neck tumors.

Risk factors for developing depressive symptoms in the immediate postoperative period after Mohs micrographic surgery.

PURPOSE: Mohs micrographic surgery (MMS) is a highly efficacious, tissue sparing method of skin cancer removal. Nevertheless, in the months to years after MMS, psychosocial distress has been described. The present study addressed the immediate period after MMS and assessed the frequency and risk factors for development of depressive symptoms. METHODS: Subjects undergoing MMS at two physician practices (JL, FS) were included in this prospective cohort study. Preoperatively, a standardized depression screening, the Patient Health Questionnaire-8 (PHQ-8), was administered. After MMS, the PHQ-8 was readministered at weeks 1, 2, 4, 6, and 12. Average PHQ-8 score by week and change from baseline PHQ-8 score were the primary outcomes. RESULTS: Sixty-three subjects were included of which 49 (78%) had a facial site. Twenty-two subjects (35%) had some increase in score during the 12-week follow-up period, of which 18 had a facial site. The oldest subjects (83-99 years, n = 14) had significantly higher PHQ-8 scores at week 4 (p < 0.01) and week 6 (p = 0.02) than all other age groups. There were no differences in scores between location groups. CONCLUSIONS: One-third of subjects had some increase in score during the follow-up period. Those in the oldest age cohort were at highest risk of increased score. In contrast to prior literature, those with facial sites were not at higher risk. This difference may be explained by increased masking during the ongoing COVID-19 pandemic. Ultimately, consideration of patients' psychologic status in the immediate postoperative period after MMS, particularly in the elderly population, may enhance perceived patient outcomes.

High-resolution full-field optical coherence tomography microscope for the evaluation of freshly excised skin specimens during Mohs surgery: A feasibility study.

Histopathology for tumor margin assessment is time-consuming and expensive. High-resolution full-field optical coherence tomography (FF-OCT) images fresh tissues rapidly at cellular resolution and potentially facilitates evaluation. Here, we define FF-OCT features of normal and neoplastic skin lesions in fresh ex vivo tissues and assess its diagnostic accuracy for malignancies. For this, normal and neoplastic tissues were obtained from Mohs surgery, imaged using FF-OCT, and their features were described. Two expert OCT readers conducted a blinded analysis to evaluate their diagnostic accuracies, using histopathology as the ground truth. A convolutional neural network was built to distinguish and outline normal structures and tumors. Of the 113 tissues imaged, 95 (84%) had a tumor (75 basal cell carcinomas [BCCs] and 17 squamous cell carcinomas [SCCs]). The average reader diagnostic accuracy was 88.1%, with a sensitivity of 93.7%, and a specificity of 58.3%. The artificial intelligence (AI) model achieved a diagnostic accuracy of 87.6 ± 5.9%, sensitivity of 93.2 ± 2.1%, and specificity of 81.2 ± 9.2%. A mean intersection-over-union of 60.3 ± 10.1% was achieved when delineating the nodular BCC from normal structures. Limitation of the study was the small sample size for all tumors, especially SCCs. However, based on our preliminary results, we envision FF-OCT to rapidly image fresh tissues, facilitating surgical margin assessment. AI algorithms can aid in automated tumor detection, enabling widespread adoption of this technique.

An Update and Review of Clinical Outcomes Using Immunohistochemical Stains in Mohs Micrographic Surgery for Melanoma.

BACKGROUND: Mohs micrographic surgery (MMS) provides optimal margin control through complete peripheral and deep margin assessment. The treatment of melanoma using MMS has historically been limited by difficulty in interpreting melanocytes using frozen sections. Immunohistochemical (IHC) staining, a technique whereby chromogen-tagged antibodies are used to detect antigens of interest, has revolutionized the surgical treatment of melanoma. OBJECTIVES: This article provides an update and literature review of current IHC stains used in MMS for melanoma, their sensitivities and specificities, and clinical outcomes. MATERIALS AND METHODS: A PubMed search was performed using keywords including "immunohistochemistry," "staining," and "Mohs surgery." Articles related to the use of IHC staining for the treatment of melanoma with MMS were included. RESULTS: Six IHC stains met the criteria for the review including melanoma antigen recognized by T cells (MART-1), SRY-related HMG-box (SOX10), microphthalmia-associated transcription factor, HMB-45, MEL-5, S-100, and preferentially expressed antigen in melanoma. CONCLUSION: The adaptation of IHC methods to frozen sections has enabled MMS to become a preferred treatment option for melanoma in special-site areas. Future studies are needed to standardize IHC techniques and to define best practices when using frozen section in the treatment of melanoma.

Novel role of fluorescent in situ hybridization technique (FISH) in recommended surgical margins of dermatofibrosarcoma protuberans: A preliminary study.

BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a rare skin tumor. There is no standard recommendation for its surgical management. The currently used histological analysis are HES (hematoxylin eosin saffron) staining and immunohistochemistry for CD34 expression in particular cases. Fluorescent in situ hybridization (FISH) technique is only used to qualify the DFSP as translocated or non-translocated and is not used as a diagnostic method. The aim of our study was to determine by FISH (as a diagnostic method) whether cancerous cells that could not be identified through HES staining±immunohistochemistry were present at the two-centimeter margins that were found to be tumor-free. METHODS: Samples from patients who underwent surgery between 2010 and 2018 were collected. Intralesional and peripheral (at 2cm margins) paraffin slides were included. An average of 7.4 slides per specimen was analyzed. Firstly, the preselected slides were reread by a senior pathologist to confirm the absence of microscopic findings of DFSP at 2cm margins. Secondly a FISH analysis was used as a quantitative diagnostic approach, in order to find the t(17;22) translocation. RESULTS: Among the seven specimens that included 2cm margins, two samples presented one or more translocations, which were not visible in standard morphology assessments at two centimeters tumor-free margins. CONCLUSIONS: FISH analysis can have a new role in defining tumor-free margins. This would reduce the incidence of disease recurrence after resection and improve the post-operative complementary care.

Management of periocular keratinocyte carcinomas with Mohs micrographic surgery and predictors of complex reconstruction: a retrospective study.

BACKGROUND: Skin cancer is the most frequent cancer worldwide and the most frequent periocular tumor. Keratinocyte Carcinomas (KC) located in periorificial areas, such as periocular tumors, are considered high-risk tumors. Mohs Micrographic Surgery (MMS) is considered the first line for the treatment of high-risk KC, providing a lower recurrence rate than conventional wide excision. OBJECTIVE: To describe the clinical-pathological features of periocular KC treated with MMS in a tertiary university center in Chile. METHODS: A single-center, retrospective study of patients with KC located on the periocular area, that underwent MMS between 2017‒2022. MMS details were recorded. RESULTS: One hundred thirteen patients with periocular carcinomas were included. The mean age was 59 ± 13 years; 52% were women. The most frequent location was the medial canthus (53%), followed by the lower eyelid (30.1%). The most frequent BCC histology was the nodular variant (59.3%). Regarding MMS, the average number of stages was 1.5 ± 0.7, and 54% of the cases required only 1 stage to achieve clear margins. To date, no recurrence has been reported. Tumors larger than 8.5 mm in largest diameter or 43.5 mm2 were more likely to require complex reconstruction. STUDY LIMITATIONS: Retrospective design and a relatively low number of patients in the SCC group. Possible selection bias, as larger or more complex cases, may have been referred to oculoplastic surgeons directly. CONCLUSION: The present study confirms the role of MMS for the treatment of periocular KCs. Periocular KCs larger than 8.5 mm might require complex reconstruction. These results can be used to counsel patients during pre-surgical visits.

Efficacy of micrographic surgery versus conventional excision in reducing recurrence for basal cell carcinoma and squamous cell carcinoma: A systematic review and meta-analysis.

The standard of care for basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) involves excision by conventional surgery (CS) with a predefined safety margin of resection or micrographic surgery (MS) with microscopic margin control. Previous studies have reported the superiority of MS in reducing recurrences for high-risk BCC and SCC. This systematic review aimed to assess MS and CS recurrence rates by including randomized clinical trials (RCTs) and cohort studies. A systematic review and meta-analysis were conducted for related studies in PubMed, LILACS, Embase, Scopus, Web of Science, CINHAL and Cochrane until May 2023. RCTs and cohorts involving patients with BCC or SCC submitted to MS and CS were included. Risk of bias assessment followed Cochrane-recommended tools for RCTs and cohorts, and certainty of evidence followed the GRADE approach. Pooled estimates were used to determine the relative risk (RR) and absolute risk difference (RD) using a random-effects model. Seventeen studies were included, two RCTs and fifteen cohorts. There were 82 recurrences in 3050 tumours submitted to MS, with an overall recurrence rate of 3.1% (95% CI 2.0%-4.7%). For CS, there were 209 recurrences in 3453 tumours, with a recurrence rate of 5.3% (95% CI 2.9%-9.3%). The combined estimate of RR was 0.48 (95% CI 0.36-0.63), without heterogeneity nor evidence of publication bias (p > 0.3). The RD resulted in 2.9% (95% CI 1.0%-4.9%; NNT = 35). Regarding subgroup analysis, the RR for BBC was 0.37 (95% CI 0.25-0.54), and RD was 3.7% (95% CI 0.8%-6.5%; NNT = 28). For SCC, RR was 0.57 (95% CI 0.29-1.13), and RD was 1.9% (95% CI 0.8%-4.7%; NNT = 53). Among primary tumours, RR was 0.39 (95% CI 0.28-0.54), and for recurrent tumours was 0.67 (95% CI 0.30-1.50). There is moderate evidence based on two RCTs, and low evidence based on 15 cohort studies that MS is superior to CS in reducing recurrences of BCCs and primary tumours. The development of protocols that maximize the cost-effectiveness of each method in different clinical scenarios is paramount.

Comparing Mohs micrographic surgery and wide local excision in the management of head and neck dermatofibrosarcoma protuberans: a scoping review.

Dermatofibrosarcoma protuberans (DFSP) is a rare, locally aggressive cutaneous sarcoma with a propensity for recurrence. Its management, particularly in the head and neck (H&N) region, presents unique challenges. This study aimed to evaluate the effectiveness of Mohs micrographic surgery (MMS) compared to wide local excision (WLE) in treating H&N DFSP and its impact on recurrence rates and tissue preservation. A comprehensive search was conducted in PubMed/MEDLINE, yielding 29 relevant studies. We included studies comparing MMS and WLE in adult patients with H&N DFSP and reporting local recurrence outcomes. Data were analyzed using random effects analysis, with a meta-analysis performed for comparative studies. Analysis of studies demonstrated a lower recurrence for MMS. Comparative analysis of five studies involving 117 patients showed a significantly lower recurrence rate in the MMS group (2%) compared to the WLE group (19%). Margin status varied between studies, with some achieving negative margins at shorter distances. In the management of H&N DFSP, MMS has emerged as a superior surgical technique, consistently associated with reduced recurrence rates and the potential for tissue preservation. The adoption of MMS should be considered for its capacity to achieve negative margins with fewer processing steps, particularly in anatomically complex regions like the H&N.

Dermatologic surgeons' approaches to acral lentiginous melanoma: a survey of the American College of Mohs Surgery.

Acral lentiginous melanoma (ALM) is a subtype of melanoma that primarily affects ethnic minorities and is associated with poor outcomes. Racial inequalities in melanoma survival, particularly between Blacks and Whites, have been well documented in the literature. There are limited data on the role of surgical approach to ALM and its contribution to the existing disparities in ALM survival. Thus, this study aimed to investigate the role of surgical approach to ALM among Mohs surgeons. The survey was distributed to members of the American College of Mohs Surgery (ACMS), with 43 physicians completing the survey. The results showed that there was no consensus among Mohs surgeons regarding the surgical approach for ALM, even for advanced stages. 74% respondents performed complete circumferential peripheral and deep margin assessment (CCPDMA) for ALM, including Mohs micrographic surgery (MMS) or en face staged excision. However, barriers such as limited training, low comfort operating on acral sites, and inadequate access to specialized biopsies were reported. Treatment recommendations varied widely regardless of the ALM stage, with no significant differences based on exposure to ALM during training, practice setting, or percent of skin of color patients served. These findings highlight the lack of guidelines and the need for more data on outcomes to support optimal management of ALM. The study emphasizes the importance of addressing healthcare disparities and improving survival outcomes, particularly for ethnic minorities affected by ALM. Consensus guidelines could help standardize treatment approaches and potentially reduce disparities in ALM management.

MMS hotspots: a cross-sectional comparison of U.S. counties with and without Mohs micrographic surgery.

Healthcare access greatly impacts skin cancer diagnosis and mortality rates. Recognition of current disparities in Mohs micrographic surgery (MMS) access can assist future policy and clinical decisions to correct them. For the years 2014-2018, the CPT codes for MMS (17,311 and 17,313) were counted on a per county level across the United States per the Medicare Centers for Medicare & Medicaid Services (CMS) Medicare Prescriber Database. Any county with 0 MMS CPT codes recorded were classified as "without MMS cases." MMS "hotspots" were identified as counties that possessed a high average number of MMS cases compared to the national average, while also being surrounded by counties that possessed a low average number of MMS cases compared to the national average. Three thousand eighty-four counties in the United States were analyzed; 785 (25%) counties were designated as "with MMS cases" and 2301 (75%) "without MMS cases." There were no significant differences in age, ethnicity distribution, or cost per enrollee between the two designations. 74% of counties with MMS cases were considered urban, while only 25% of those without cases were urban (p < 0.01). The median household income was markedly higher in counties with MMS cases ($71,428 vs. $58,913, p < 0.01). With respect to education, more individuals in counties with MMS cases possessed their General Education Development (GED) (89% vs. 86%, p < 0.01) or a college degree (30% vs. 19%, p < 0.01). Forty-nine counties were considered MMS "hotspots." The density of MMS procedures varies greatly based on geography, maintaining the urban-rural disparity matched by the distribution of MMS surgeons. Additionally, there remains a wide income and educational gap between counties with and without MMS. Identifying MMS hotspots may facilitate further investigation into potential surgical access disparities.

Reported Outcome Measures in Mohs Micrographic Surgery in Studies With Defined Techniques for Embedding and Processing of Tissue: A Systematic Review.

BACKGROUND: Mohs micrographic surgery (MMS) is a technique that combines surgical excision and histologic evaluation to achieve higher cure rates for skin cancer than traditional surgical excision. Competing performance measures have fostered numerous histologic techniques for MMS. OBJECTIVE: To analyze differences in primary outcomes in the published literature regarding the technique of tissue processing and embedding during the MMS process. METHODS: A systematic review was performed of the published literature in MEDLINE, PubMed, Embase, and Cochrane library that included a description of the manipulation of tissue during the grossing and embedding steps of MMS. RESULTS: Inclusion criteria were met by 61 articles. Of these studies, the cure/recurrence rate was assessed in 1 article (1.6%), tissue conservation was assessed in 47 (77%), time-saving was assessed in 35 (57%), cost-saving was assessed in 6 (10%), and decreased artifact were assessed in 20 (33%). CONCLUSION: There is a lack of standardization for assessing clinical outcomes in the published literature regarding MMS process techniques. Cure is a critical outcome in studies comparing MMS processing methodologies.

Racial-Ethnic, Education, and Socioeconomic Differences in the Treatment of Head and Neck Melanoma in situ: A Surveillance Epidemiology and End Results Population-Based Analysis.

BACKGROUND: Incidence and treatment disparities for cutaneous melanomas have been documented among racial and sociodemographic minorities. However, the association between treatment types, race, and socioeconomic status remains unknown. OBJECTIVE: To characterize treatment differences for head and neck melanoma in situ (MIS) and lentigo maligna (LM) based on race and sociodemographic variables. MATERIALS AND METHODS: A population-based retrospective cohort study of the Surveillance Epidemiology and End Results database (1998-2016) was performed. Univariate and multivariate logistic regression modeling evaluated the association of race and US census-reported sociodemographic factors with Mohs micrographic surgery (MMS) utilization. RESULTS: A total of 76,328 adult patients with head and neck MIS/LM were included. MMS accounted for 11.8% of total cases, with increased utilization observed since 1998-2002. Compared with areas with greater percentages of individuals completing high school (first quartile), patients living in the second (Odds ratio [OR] 0.71; 95% confidence interval [CI] 0.64-0.80; p < .001), third (OR 0.74; 95% CI 0.63-0.86; p < .001), and fourth quartiles (OR 0.44; 95% CI 0.35-0.55; p < .001) were less likely to undergo MMS for their MIS/LM. CONCLUSION: Educational efforts and awareness can bridge the knowledge gaps of appropriate treatment in patients with head and neck MIS/LM.

Incidence and Survival Outcomes of Dermatofibrosarcoma Protuberans From 2000 to 2020: A Population-Based Retrospective Cohort Analysis.

BACKGROUND: Recent changes in the incidence and survival of dermatofibrosarcoma protuberans (DFSP) have not been described. OBJECTIVE: To characterize the incidence and survival of DFSP. MATERIALS AND METHODS: A retrospective cohort study of patients with DFSP from 2000 to 2020 in the Surveillance, Epidemiology, and End Results database was performed. Cox and Fine-Gray regression models were used to assess overall and DFSP-specific survival. RESULTS: The incidence of DFSP has not changed from 2000 to 2020 with 4.6 cases/million person-years, with higher rates in dark-skinned and middle-age individuals. Factors associated with overall mortality in DFSP patients include advanced age ( p < .0001), male sex (hazard ratio [HR] 1.8, p < .0001), larger tumors (HR 1.002 per millimeter, p < .001), lower household income (HR 1.8, p = .0002), and lower extremity location (HR 1.7, p = .008). Mohs surgery is associated with improved overall survival (HR 0.4, p = .02). Large tumor size (6.0+ cm, HR 6.7, p = .01) and advanced age (age 80+ years, HR 21.3, p = .003) were associated with worse DFSP-specific mortality. CONCLUSION: Dermatofibrosarcoma protuberans incidence has remained constant from 2000 to 2020. Increasing age and tumor size, decreased income, male sex, and lower extremity location are associated with worsened survival. Mohs surgery is associated with improved overall survival. Increased age and tumor size are associated with worsened DFSP-specific mortality.