Comparison of surgical margins for lentigo maligna versus melanoma in situ

Intraoperative Immunohistochemistry During Mohs Micrographic Surgery and Staged Excision Decreases Local Recurrence Rates for Invasive Cutaneous Melanoma: A Systematic Review and Meta-Analysis

BACKGROUND

Mohs micrographic surgery (MMS) is increasingly used to treat cutaneous melanoma. However, it is unclear whether intraoperative immunohistochemistry (IHC) improves surgical outcomes.

OBJECTIVE

To determine whether intraoperative IHC during MMS and staged excision is associated with a decreased risk of poor surgical outcomes.

MATERIALS AND METHODS

Search of 6 databases identified comparative and noncomparative studies that reported local recurrence after MMS or staged excision with or without IHC for melanoma. Random-effects meta-analysis was used to estimate pooled local recurrence rates, nodal recurrence, distant recurrence, and disease-specific mortality.

RESULTS

Overall, 57 studies representing 12,043 patients with cutaneous melanoma and 12,590 tumors met inclusion criteria. Combined MMS and staged excision with IHC was associated with decreased local recurrence in patients with invasive melanoma (0.3%, 95% CI: 0-0.6) versus hematoxylin and eosin alone (1.8%, 95% CI: 0.8%-2.8%) [ p < .001]. Secondary outcomes including nodal recurrence, distant recurrence, and disease-specific mortality were not significantly different between these 2 groups. Study heterogeneity was moderately-high.

CONCLUSION

Local recurrence of invasive melanoma is significantly lower after MMS and staged excision with IHC as opposed to without IHC. These findings suggest that the use of intraoperative IHC during MMS or staged excision should strongly be considered, particularly for invasive melanoma.Trial Registration PROSPERO Identifier: CRD42023435630.

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.

Mohs Micrographic Surgery for Invasive Melanoma Allows for Tissue Preservation Compared With Wide Local Excision: A Retrospective Cohort Study

BACKGROUND

While increasing evidence supports the safety and effectiveness of immunohistochemistry-assisted Mohs micrographic surgery (MMS) for superficially invasive melanoma, there is a paucity of the literature investigating its effect on final defect size.

OBJECTIVE

To evaluate the tissue sparing effect of MMS for melanoma.

MATERIALS AND METHODS

Three hundred and twenty-eight patients with early-stage (T1a/T1b) cutaneous melanomas treated with MMS from January 2008 to December 2018 were evaluated. Measured defect sizes after Mohs tumor extirpation were compared with anticipated defect size that would result from standard-margin wide local excision (WLE). Average actual versus anticipated defect areas were compared using a paired t-test (95% confidence intervals).

RESULTS

The following groups demonstrated a significantly smaller defect area for MMS-treated tumors when compared with anticipated standard-margin WLE defect: All tumors combined (13.8 cm2 vs 10.4 cm2, p < .001), tumors requiring 1 stage (13.6 cm2 vs 10.1 cm2,p < .001), and tumors requiring 2 stages (13.2 cm2 vs 10.5 cm2, p = .004). The majority of patients (83.5%, n = 274) achieved clear margins with 1 stage.

CONCLUSION

Immunohistochemistry-assisted MMS for early-stage invasive melanoma is associated with smaller final defect size and overall tissue sparing effect compared with standard WLE margins.

Lentigo Maligna Treatment-An Update

Lentigo maligna (LM) is a melanoma in situ that is prevalent in chronically sun-damaged skin. Characterized by a slow growth pattern and high mutation rates due to chronic UV exposure, LM poses diagnostic and therapeutic challenges, particularly given its tendency to mimic other skin lesions and its occurrence in cosmetically sensitive areas. Its diagnosis is based on an integrated approach using dermoscopy and reflectance confocal microscopy (RCM). Despite its slow progression, LM can evolve into lentigo maligna melanoma (LMM), making its treatment necessary. Treatment modalities encompass both surgical and non-surgical methods. Surgical treatments like Wide Local Excision (WLE) and Mohs Micrographic Surgery (MMS) aim for clear histological margins. WLE, a standard melanoma surgery, faces challenges from LM's subclinical extensions, which increase the recurrence risk. MMS, effective for large or poorly defined lesions, is defined by precise margin control while considering cosmetic outcomes. Non-surgical options, including radiotherapy and imiquimod, are alternatives for non-surgical candidates. Radiotherapy has been effective since the 1950s, offering good control and cosmetic results, especially for older patients. Imiquimod, an immunomodulator, shows promise in treating LM, though its application remains off-label. The increasing incidence of LM/LMM necessitates a balance in treatment choices to minimize recurrence and maintain cosmetic integrity. A multidisciplinary approach, integrating clinical examination with dermoscopy and RCM and histological assessment, is essential for accurate diagnosis and effective LM management.

Lentigo maligna: a review

Lentigo maligna (LM) is a melanoma in situ with distinct clinical features and histology. It commonly affects men after the sixth decade of life. Incidence rates of LM have increased based on early 21st century data from different countries; however, data are suboptimal. Data from England show a plateauing crude incidence between 2013 and 2019. By comparison, invasive melanoma and other types of melanoma in situ commonly appears in younger age groups (median age 58 and 67 years old, respectively) and incidence is rising. The most important risk factors for LM include fair skin and cumulative ultraviolet solar radiation exposure. Although LM is limited to the epidermis and connected skin adnexa, it may progress to invasive LM melanoma. The reported rate of malignant progression varies, reflecting a challenge for LM epidemiology research as often lesions are removed on diagnosis. LM poses a challenge in diagnosis and management. Although it can be diagnosed clinically or dermoscopically, histopathological assessment of biopsied skin tissue remains the gold standard. Reflectance confocal microscopy allows for better appreciation of the complexity of LM at a cellular level, often progressing beyond clinical margins. Management of LM may involve Mohs micrographic surgery or excision, although recurrence may occur even with 5 mm clinical margins. Imiquimod cream may be effective, but incomplete treatment and recurrence has been reported. Conservative management with observation or radiotherapy may be used in selected patients' cases. Five-year net survival rates are excellent. This paper reviews the natural history, epidemiology, aetiology, pathogenesis, diagnosis and management of LM.

Disease-specific survival of malignant melanoma after Mohs micrographic surgery is not impacted by initial margins: A systematic review and meta-analysis

Background

During Mohs surgery for melanoma, evidence has demonstrated that many surgeons opt for smaller initial margins than traditionally recommended (0.5 cm for in situ and 1 cm for invasive). Literature regarding surgical outcomes based on initial margin is sparse.

Objective

To determine differences in disease-specific survival of melanoma after Mohs micrographic surgery for varied initial surgical margins.

Methods

A literature search was conducted on February 14, 2022, from MEDLINE via PubMed (1946-present), Embase (1974-present), Central (1991-present), and Scopus (1960-present). The primary outcome was disease-specific mortality.

Results

Nineteen studies were included for final analysis. The overall disease-specific mortality rate of melanoma in all included studies was 0.5% (CI, 0.1-0.8; P, .010). Disease-specific mortality for 1 to 5, 5, and 6 to 10 mm categories were 0.4% (CI, 0.0-0.9; P, .074), 0.7% (CI, 0.2-1.3; P, .2-1.3), and 0.4% (CI, -0.9 to 1.8; P, .524), respectively. None of the variances across initial margin categories were statistically significant.

Limitations

Early-stage melanomas have low overall mortality rates. In our associated article, initial margins of 5 to 10 mm were shown to have the lowest rates of local recurrence.

Conclusions

In this systematic review and meta-analysis, melanoma-specific mortality was not significantly impacted by the initial surgical margin taken during Mohs micrographic surgery.

Histologic margin status is a predictor of relapse in lentigo maligna melanoma

BACKGROUND

Most surgical margins for lentigo maligna melanomas reported in the literature are clinical and not histologic.

OBJECTIVES

We sought to determine whether histologic margin status is an independent predictor of progression.

METHODS

Clinicopathologic information of 268 invasive lentigo maligna melanomas diagnosed from 1990-2019 were analyzed. Statistical analyses were performed using Cox proportional hazards model and Boruta method.

RESULTS

A total of 75% of the lesions were located on the head and neck. The range of follow-up for all patients was 0 to 31.8 years (median, 10.2 years). Time to local recurrence ranges from 0 to 20 years (median, 3 years). Progression developed in 54 (20.1%) of 268 patients. Local recurrence was seen only in 36 (13.4%), both local recurrence and subsequent metastasis in 7 (2.6%), and only metastasis in 11 (4.1%) of 268 patients. Histologic margin status (positive and close/<3 mm) and tumor site (head and neck location) significantly correlated with worse progression-free survival.

LIMITATIONS

Single institution and retrospective study.

CONCLUSIONS

Histologic margin status is the strongest predictor of progression for lentigo maligna melanoma. Patients with positive or close/<3 mm histologic margins should consider a re-excision due to the increased risk of relapse.

Outcomes of invasive melanoma of the head and neck treated with Mohs micrographic surgery - A multicenter study

BACKGROUND

There are no randomized controlled trials to guide surgical margins for invasive head and neck (H&N) melanoma using conventional excision. Mohs micrographic surgery (MMS) has shown improved local recurrence rates and survival for invasive H&N melanomas.

OBJECTIVE

Determine local recurrence (LR), nodal recurrence, and distant recurrence rates, and disease specific survival for invasive melanoma of the H&N treated with MMS.

METHODS

A retrospective multicenter study of 785 cases of invasive H&N melanoma treated with MMS using frozen sections with melanoma antigen recognized by T-cells 1 immunohistochemical staining was performed to evaluate long-term outcomes over 12-years.

RESULTS

785 melanomas (thickness: 0.3 mm-8.5 mm) were treated with MMS. LR, nodal recurrence, and distant recurrence rates were 0.51% (4/785), 1.0% (8/785), and 1.1% (9/785) respectively. For T1, T2, T3, and T4 tumors LR was 0.16% (1/636), 1.18% (1/85), 2.22% (1/45), and 5.26% (1/19), respectively. Five and 10-year disease specific survival were 96.8% (95% CI 95.0% to 98.5%) and 93.4% (95% CI 88.5% to 98.3%).

LIMITATIONS

A nonrandomized retrospective study.

CONCLUSION

MMS achieves significant improvements in LR compared to a meta-analysis of historical cohorts of patients treated with conventional excision. MMS should be considered an important surgical option for invasive H&N melanoma.

Spaghetti Technique Versus Wide Local Excision for Lentigo Maligna Affecting the Head and Neck Regions: Surgical Outcome and Descriptive Analysis of 79 Cases from a Single Practice Cohort

INTRODUCTION

Lentigo maligna is a subtype of melanoma in situ that typically affects the head and neck region with an increasing incidence. Margin-controlled techniques, such as spaghetti technique (ST), have gained popularity over wide local excision (WLE) with a margin of 5 mm.

OBJECTIVES

To evaluate the outcomes of lentigo maligna cases in the head and neck area treated by either WLE or ST in a tertiary referral hospital. The secondary goal was to describe the demographic and clinical characteristics of our series.

METHODS

Cohort study of patients diagnosed with lentigo maligna on the head and neck region between January 2014 and February 2022 in a tertiary hospital.

RESULTS

In total, 79 lentigo maligna were studied, corresponding to 77 patients. Fifty-three lesions (67%) were treated with WLE and 26 (33%) with ST. The mean age of the patients was 73 years and 58% were men. Most of the tumors were located on the cheek (50%) and mean lesion diameter was 2.2 cm for the ST group and 1.2 cm for the WLE group. Mean duration follow-up was 44 months. There were two local recurrences in the WLE group (2/53; 3.7%) and none in the ST group.

CONCLUSIONS

Both WLE and ST are appropriate surgical approaches for lentigo maligna. ST offers an efficient alternative to Mohs surgery for treating lentigo maligna in the head and neck area, especially when guided by reflectance confocal microscopy.

[Micrographic controlled surgery in everyday dermatosurgery]

Micrographic controlled surgery (MCS) has become established in dermatosurgery in recent years and includes various methods to enable the histologically proven complete resection of malignant cutaneous tumors, while at the same time sparing tumor-free tissue in the immediate vicinity as much as possible. MCS is of great importance in the surgical treatment of cutaneous malignancies in so-called problem locations and aggressive tumor subtypes. Indications for MCS include basal cell carcinoma, cutaneous squamous cell carcinoma, Bowen's disease and Bowen's carcinoma, melanoma in chronic light-damaged skin with acral lentiginous melanoma, dermatofibrosarcoma protuberans (DFSP), and Merkel cell carcinoma. However, other tumor entities are also treated using MCS, such as extramammary Paget's disease and various cutaneous sarcomas. All procedures subsumed under MCS have in common the marking of the surgical specimen for topographical orientation, which provides assignment of remaining tumor remnants. Various methods of MCS (3D histology, the horizontal method or Mohs surgery) are presented in this article. Furthermore, this article aims to raise awareness of the possibilities and limitations of micrographically controlled surgery.

Semiconducting Titanate Supported Ruthenium Clusterzymes for Ultrasound-Amplified Biocatalytic Tumor Nanotherapies

The external-stimulation-induced reactive-oxygen-species (ROS) generation has attracted increasing attention in therapeutics for malignant tumors. However, engineering a nanoplatform that integrates with efficient biocatalytic ROS generation, ultrasound-amplified ROS production, and simultaneous relief of tumor hypoxia is still a great challenge. Here, we create new semiconducting titanate-supported Ru clusterzymes (RuNC/BTO) for ultrasound-amplified biocatalytic tumor nanotherapies. The morphology and chemical/electronic structure analysis prove that the biocatalyst consists of Ru nanoclusters that are tightly stabilized by Ru-O coordination on BaTiO₃ . The peroxidase (POD)- and halogenperoxidase-like biocatalysis reveals that the RuNC/BTO can produce abundant •O₂ ^- radicals. Notably, the RuNC/BTO exhibits the highest turnover number (63.29 × 10^-3 s^-1 ) among the state-of-the-art POD-mimics. Moreover, the catalase-like activity of the RuNC/BTO facilitates the decomposition of H₂ O₂ to produce O₂ for relieving the hypoxia of the tumor and amplifying the ROS level via ultrasound irradiation. Finally, the systematic cellular and animal experiments have validated that the multi-modal strategy presents superior tumor cell-killing effects and suppression abilities. We believe that this work will offer an effective clusterzyme that can adapt to the tumor microenvironment-specific catalytic therapy and also provide a new pathway for engineering high-performance ROS production materials across broad therapeutics and biomedical fields.

Local Recurrence Rates of Malignant Melanoma After Mohs Micrographic Surgery Are Lowest With 5- to 10-mm Initial Margins: A Systematic Review and Meta-Analysis

BACKGROUND

Current consensus guidelines have discouraged the use of sub-0.5-cm (in situ) and sub-1-cm (invasive) margins when performing Mohs micrographic surgery (Mohs) for melanoma, with minimal evidence to guide this recommendation.

OBJECTIVE

To compare melanoma local recurrence rates after Mohs based on initial margin size.

MATERIALS AND METHODS

A systematic review and meta-analysis was conducted with search terms including Mohs micrographic surgery, surgical margin, recurrent disease, and melanoma.

RESULTS

Forty-three studies were included. The 5- to 10-mm margin category had a statistically significant lower local recurrence compared with 1- to 5-mm and 5-mm categories. Recurrence for 1- to 5-mm, 5-mm, 5- to 10-mm, and 10-mm categories were 2.3% (CI 0.8-3.5, p < .001), 1.4% (CI 0.6-2.2, p < .001), 0.3% (CI 0.2-0.5, p < .001), and 6.1% (CI -6.7 - 18.8, p = .349), respectively. Number of stages for 1 to 5, 5, 5 to 10, and 10-mm categories were 1.8, 1.8, 1.6, and 1.6, respectively. There was no statistically significant difference between the groups (p = .694).

CONCLUSION

Five- to 10-mm margins were associated with the lowest local recurrence rates. A 5- to 10-mm initial margin should be considered where other factors (tumor characteristics, anatomical or functional considerations) allow.

Limitations in the literature regarding Mohs surgery and staged excision for melanoma: A critical review of quality and data reporting

BACKGROUND AND OBJECTIVES

The literature supporting Mohs micrographic surgery and staged excision in treating primary cutaneous melanoma is growing but has not been critically reviewed for bias.

METHODS

Articles concerning Mohs micrographic surgery and staged excision for melanoma were assessed using modified "Risk of Bias in Non-randomized Studies of Interventions" (ROBINS-I) criteria, which measures bias in 7 categories.

RESULTS

Forty-seven of 48 (97.9%) studies reviewed had serious or critical bias. None were randomized controlled trials. The most frequent cause of critical bias was poorly defined outcomes. The least frequent form of bias observed was change in intervention.

LIMITATIONS

The modified ROBINS-I criteria cannot account for all study limitations. Modification of the criteria leads to some degree of subjectivity.

CONCLUSION

The current body of literature suffers from limitations due to serious or critical bias in 1 or more ROBINS-I criteria. Local recurrence rate definitions are often poorly defined or not defined at all. Longer follow-up times, clear tumor classifications, and prospective, randomized study designs are necessary to improve the quality of future research.

Lentigo maligna melanoma mapping using reflectance confocal microscopy correlates with staged excision: A prospective study

BACKGROUND

Lentigo maligna/lentigo maligna melanoma (LM/LMM) can present with subclinical extension that may be difficult to define preoperatively and lead to incomplete excision and potential recurrence. Preliminarily studies have used reflectance confocal microscopy (RCM) to assess LM/LMM margins.

OBJECTIVE

To evaluate the correlation of LM/LMM subclinical extension defined by RCM compared with the gold standard histopathology.

METHODS

Prospective study of LM/LMM patients referred for dermatologic surgery. RCM was performed at the clinically defined initial surgical margin followed by margin-controlled staged excision with paraffin-embedded tissue, and histopathology was correlated with RCM results.

RESULTS

Seventy-two patients were included. Mean age was 66.8 years (standard deviation, 11.1; range, 38-89); 69.4% were men. Seventy of 72 lesions (97.2%) were located on the head and neck with mean largest clinical diameter of 1.3 cm (range, 0.3-5). Diagnostic accuracy for detection of residual melanoma in the tumor debulk (after biopsy) had a sensitivity of 96.7% and a specificity of 66.7% when compared with histopathology. RCM margin assessment revealed an overall agreement with final histopathology of 85.9% (κ = 0.71; P < .001).

LIMITATIONS

No RCM imaging beyond initial planned margins was performed.

CONCLUSION

RCM showed moderate to excellent overall agreement between RCM imaging of LM/LMM and histopathology of staged excision margins.

Treatment of periocular lentigo maligna with topical 5% Imiquimod: a review

Lentigo Maligna is a benign subtype of melanoma in situ and can progress to lentigo maligna melanoma, which is invasive. Complete surgical excision is the gold standard of treatment but requires large margins. If affecting the peri-ocular region, surgical excision leads to extensive defects, complex reconstructions, and functional impairment of the protection of the ocular surface. Here we review the reported literature about the use of Imiquimod 5% topical cream for lentigo maligna of the eyelid, the treatment outcomes, side effects and tolerance. In addition, the side effects of imiquimod treatment of non-LM lesions are described to help better inform the decision-making process. Treatment for peri-ocular Lentigo maligna showed a 56-86% complete treatment response and a 90% tolerability rate. However, reported treatment protocols vary and histopathological confirmation of clearance was only obtained in 56%. Further studies are required to determine the optimal treatment protocol to maximise clearance rates. Overall, Imiquimod was well tolerated in the peri-ocular area.

Lentigo maligna (melanoma): A systematic review and meta-analysis on surgical techniques and presurgical mapping by reflectance confocal microscopy

Because of an increased risk of local recurrence following surgical treatment of lentigo maligna (melanoma) (LM/LMM), the optimal surgical technique is still a matter of debate. We aimed to evaluate the effect of different surgical techniques and reflectance confocal microscopy (RCM) on local recurrence and survival outcomes. We searched MEDLINE, Embase and PubMed databases through 20 May 2022. Randomized and observational studies with ≥10 lesions were eligible for inclusion. Bias assessment was performed using the Methodological Index for Non-Randomized Studies instrument. Meta-analysis was performed for local recurrence, as there were insufficient events for the other clinical outcomes. We included 41 studies with 5059 LM and 1271 LMM. Surgical techniques included wide local excision (WLE) (n = 1355), staged excision (n = 2442) and Mohs' micrographic surgery (MMS) (n = 2909). Six studies included RCM. The guideline-recommended margin was insufficient in 21.6%-44.6% of LM/LMM. Local recurrence rate was lowest for patients treated by MMS combined with immunohistochemistry (<1%; 95% CI, 0.3%-1.9%), and highest for WLE (13%; 95% CI, 7.2%-21.6%). The mean follow-up varied from 27 to 63 months depending on surgical technique with moderate to high heterogeneity for MMS and WLE. Handheld-RCM decreased both the rate of positive histological margins (p < 0.0001) and necessary surgical stages (p < 0.0001). The majority of regional (17/25) and distant (34/43) recurrences occurred in patients treated by WLE. Melanoma-associated mortality was low (1.5%; 32/2107), and more patients died due to unrelated causes (6.7%; 107/1608). This systematic review shows a clear reduction in local recurrences using microscopically controlled surgical techniques over WLE. The use of HH-RCM showed a trend in the reduction in incomplete resections and local recurrences even when used with WLE. Due to selection bias, heterogeneity, low prevalence of stage III/IV disease and limited survival data, it was not possible to determine the effect of the different surgical techniques on survival outcomes.

Association between excision margins and local recurrence in 1407 patients with primary in situ melanomas

Background

Reliable evidence to guide the management of melanoma in situ (MIS) and minimize the risk of recurrence is lacking.

Objective

To identify clinicopathological predictors of local recurrence (LR) in patients with MIS and evaluate long-term outcomes according to pathological excision margins.

Methods

A case-control study of patients with MIS treated at a large Australian melanoma treatment center from January 2008 to December 2012 was undertaken. Clinicopathological characteristics of patients who developed LR and those who did not were compared.

Results

LR developed in 34 of 1407 patients with MIS (2.5%). Median time to LR was 20 months. The primary lesion was removed with pathological margins <4 mm (P < .001) in 67.6 % of patients with LR. Four patients died of metastatic melanoma following LR. Comparing patients with pathological margins <4 mm and ≥4 mm, the former were older (>60y, P < .001), more frequently had MIS on the head or neck (P < .001), had a greater LR rate (P < .001), and had a higher mortality from all causes (P < .001).

Limitations

Retrospective, single-institution study.

Conclusions

Pathological margins of ≥4 mm should be considered for patients with MIS who are treated with standard surgical excision and assessed by examining serial slices taken from the formalin-fixed, paraffin-embedded specimen.

Variance from published guidelines and changes in temporal trends in the management of cutaneous malignant melanoma: a 5-year update

This study aimed to assess the current management of melanoma from relative to present guidelines and determine changes 5 years ago. An eight-question survey was sent to practicing US dermatologists using the same methodology and questions from our JAAD study. Overall, saucerization/scoop biopsy (48%) was the most commonly used method. The most commonly chosen margin for melanoma in-situ (MMIS) removal was 6-10 mm (51% of respondents). For CMM with a depth greater than 1 mm, the most commonly chosen margins were in the 1.1-1.9 cm range (55% of respondents). More respondents referred cases of MMIS and CMM out for treatment as compared to 2016. Academic dermatologists in 2021 were 8% less likely to treat MMIS as compared to all other practice types in 2021, whereas 7% more likely to treat CMM greater than 1 mm. Academic dermatologists in 2016, as compared to 2021, were 4% more likely to treat MMIS and 19% more likely to treat CMM greater than 1 mm. A total of 91% of respondents reported having some change in their management of CMM. Our study findings suggest that a knowledge gap still exists representing a continued educational opportunity to more effectively distribute and implement CMM management guidelines.

Evidence from Clinical Studies Related to Dermatologic Surgeries for Skin Cancer

Simple Summary

Although significant progress in pharmacotherapy for skin cancer has been made in the past several years, surgical removal of primary skin cancer is still the first choice of treatment unless distant metastases are evident. In the surgical treatment of primary skin tumors, the surgical margin is critical not only for reducing the possibility of tumor recurrence but also for minimizing the cosmetic and functional complications associated with wide local excision. In contrast, dermatologic surgeries including lymph node dissection and skin graft can cause various complications, and these complications are frequently associated with significant morbidity and discomfort. In this review, we summarize the evidence from previous clinical studies regarding the optimal surgical margin for skin cancer and the methods for diminishing the complications associated with dermatologic surgery.

Abstract

Despite the significant progress made in the past several years in pharmacotherapies for skin cancer, such as BRAF/MEK inhibitors, immune checkpoint inhibitors, and Hedgehog pathway inhibitors, surgical removal of primary skin cancer is still the first choice of treatment unless distant metastases are evident. In cases of lymph node metastases with clinically palpable lymphadenopathy, lymph node dissection (LND) is typically performed for most skin cancers. In the surgical treatment of primary skin tumors, the surgical margin is critical not only for reducing the possibility of tumor recurrence but also for minimizing the cosmetic and functional complications associated with wide local excision. In contrast, dermatologic surgery can cause various complications. Although skin graft is frequently used for reconstruction of the surgical defect, extensive graft necrosis may develop if optimal stabilization of the graft is not obtained. LND also sometimes causes complications such as intraoperative or postoperative bleeding and postoperative lymphoceles. Moreover, as in other types of surgery, surgical site infection, intraoperative anxiety, and intraoperative and postoperative pain may also develop. These complications are frequently associated with significant morbidity and discomfort. In this review, we summarize the evidence from previous clinical studies regarding the optimal surgical margin for skin cancer and the methods for diminishing the complications associated with dermatologic surgery.

Lentigo Maligna of the head and neck: A retrospective study assessing surgical excision margins in a South African population

Background

Lentigo maligna (LM) is a subtype of melanoma in situ that occurs on sun-damaged skin and is associated with significant subclinical extension beyond the clinical margins of the lesion.

Objectives

This study aimed to determine if the standard recommended tumor excision margins for LM are adequate to achieve a 97% clearance rate and if any patient or tumor characteristics warranted wider margins.

Methods

This study is a retrospective chart review of all patients who were diagnosed with LM of the head and neck and treated with staged excision.

Results

The study included 64 patients. With a 6 mm surgical excision margin, only 60.9% of LM were completely excised. A 9 mm margin resulted in complete clearance of 71.9% of LM cases, and a 12 mm margin resulted in complete clearance in 90.6%. A surgical excision margin of 18 mm would have been required to excise 96.7% of tumors completely. Recurrent tumors (P = .01) and tumor size larger than 20 mm were associated with wider surgical excision margins (P = .154).

Conclusion

This study of LM in a South African population corroborates that the standard surgical excision margins recommended by international melanoma guidelines for LM are inadequate to achieve a 97% clearance rate.

Recurrence Rate for Melanoma Excised by Mohs Micrographic Surgery Without Immunostaining

BACKGROUND

Mohs micrographic surgery (MMS) is becoming increasingly popular for the treatment of cutaneous melanoma (CM) as multiple studies have demonstrated favorable outcomes for local recurrence and overall survival.

OBJECTIVE

To analyze the outcomes of noninvasive (NIM) and invasive melanomas (IM) using MMS with fresh frozen sections. The primary outcome was local recurrence. The secondary outcome was to identify mean surgical margins based on tumor type and location.

METHODS

Retrospective cohort study of 224 cases of CM treated from 2006 to 2016 at a tertiary academic center with MMS and fresh frozen sections by a single Mohs surgeon.

RESULTS

The overall recurrence rate was 2.6% with a mean follow-up of 36.2 months. The recurrence rate for NIM versus IM was 1.6% and 7%, respectively. The mean margins for NIM and IM were 7.9 mm and 10.1 mm, respectively. These varied by tumor site and location.

CONCLUSION

This study supports the use of MMS in the treatment of CM and highlights how narrower surgical margins for NIM of the head and neck can be achieved without increasing risk of local recurrence.

Principles of Surgery in Head and Neck Cutaneous Melanoma

Surgical management of head and neck melanoma starts from the primary biopsy of the cutaneous site by a narrow excision with a 1 to 3 mm margins. The margin should include the whole breadth and sufficient depth of the lesion. The key is not to transect the lesion. With the advent of molecular testing, gene expression profiling, and immunotherapies, the surgical management of advanced melanoma has changed. Sentinel lymph node biopsy is an essential armamentarium for T2a and higher staging/greater than 1 mm thick and advance stage disease. Molecular pathogenesis and cancer immunology are recognized in the recent treatment protocols along with surgery in advanced stages of melanoma.

Mohs Micrographic Surgery for the Treatment of Cutaneous Melanomas of the Head and Neck

Surgical excision achieving clear histologic margins remains the mainstay treatment for primary cutaneous melanoma. Tumors of the head and neck, particularly those arising in chronically sun-damaged skin, often demonstrate extensive and asymmetric subclinical extension. Over the decades, this has proven to be a significant problem for tumors arising on the head and neck, as anatomic and functional complexities of these areas have led to suboptimal surgical treatment, yielding unacceptably high rates of local recurrence and persistently positive margins with traditional wide local excision. Patients who undergo Mohs micrographic surgery may have improved survival over those who undergo wide local excision.

An Engineered Protein-Au Bioplaster for Efficient Skin Tumor Therapy

Melanoma is the most lethal malignancy in skin cancer and may occur at any site and express melanocytes. Due to malignant melanoma's invasion and migration nature, conventional therapies make it challenging to remove the whole tumor tissue while undertaking the high risks of tumor recurrence. Regarding the emerging targeted therapies and immunotherapy, drug resistance and low immunotherapeutic activity remain significant challenges. It is thus becoming urgently important to develop alternative strategies for melanoma therapy. Herein, a novel bifunctional protein-based photothermal bioplaster (PPTB) is developed for non-invasive tumor therapy and skin tissue regeneration. The complexation of adhesive protein and gold nanorods (GNRs) endow the obtained PPTB with good biocompatibility, controllable near-infrared (NIR) light-mediated adhesion performance, and high photothermal performance. Therefore, the PPTB bioagent facilitates skin adhesion and effectively transfers heat from skin to tumor. This behavior endows PPTB capability to eradicate skin tumors conveniently. Thus, the assembly strategy enables this hybrid bioplaster to hold great potential for skin-related tumor treatment.

No Recurrence in Primary Invasive Stage 1a and 1b Melanoma and Melanoma in Situ Treated With Serial Disk Staged Excision

BACKGROUND

Optimal surgical treatment modality for invasive melanoma (IM) and melanoma in situ (MIS) has been debated with proponents for standard wide local excision (WLE), serial disk staged excision, and Mohs micrographic surgery.

OBJECTIVE

The purpose of this study is to identify the recurrence rates and surgical margins of invasive stage 1 melanoma and MIS lesions using serial disk staged excision technique with rush permanent processing and "bread loafing" microscopic analysis.

MATERIALS AND METHODS

Recurrence rates and surgical margins of 63 IM and 207 MIS at the University of California Dermatology Surgery Unit were retrospectively reviewed.

RESULTS

No recurrences were observed with average follow-up of 34 and 36 months for IM and MIS, respectively (range, 10-92 months). Average surgical margins were 19.8 mm (SD 9.7) for IM and 12.1 mm (SD 12.2) for MIS.

CONCLUSION

This SSE technique for the treatment of IM and MIS is comparable in efficacy to other SSE techniques, and it offers physicians a simple and accessible alternative to WLE and MMS.

Differences Between Recommended Surgical Margins and Measured Histological Margins in Malignant Melanoma In Situ and Malignant Melanomas

ABSTRACT

Wide local excision (WLE) using appropriate surgical margins is the standard surgical management for malignant melanoma in situ (MMIS) and primary cutaneous malignant melanoma (MM). The actual width of the histologic margins is frequently not assessed, whereas narrow histologic margins are associated with an increase in local melanoma recurrence. Our objective was to analyze the actual measured histological margins of WLE specimens of MMIS and MM cases and compare them with their recommended surgical margins. A retrospective study of formalin fixed specimens of MMIS and invasive MM treated with WLE from a large university-affiliated dermatopathology laboratory was conducted. Among a total of 164 MMIS and 128 MM cases, 14 MMIS (8.5%) and 7 MM (5.9%) had positive lateral margins. The median histologic margin for MMIS, after a 15% tissue shrinkage adjusted, was 2.7 mm [1.3-3.9] for LM type and 3.9 mm [2.3-5.6] for non-LM type, in contrast to the recommended 5-mm margin. In 96 MM of T1 type (≤1.0 mm), the median adjusted histologic margin was 6.7 mm [3.5-9.1] in contrast to the recommended 10-mm margin. These results show that measured and adjusted median histologic margins in WLE specimens in both MMIS and MM of T1 type were significantly narrower than the recommended surgical margins, regardless of anatomic location. These differences are concerning, whether they reflect clinicians' intentional or unintentional deviation from recommended guidelines.

A practical guide on the use of imiquimod cream to treat lentigo maligna

Lentigo maligna (LM) is a common in situ melanoma subtype arising on chronically sun-damaged skin and mostly affects the head and neck region. Localisation in cosmetically sensitive areas, difficulty to obtain wide resection margins and advanced patient age/comorbidities have encouraged investigation of less invasive therapeutic strategies than surgery in managing complex cases of LM. Radiotherapy and imiquimod have emerged as alternative treatment options in this context. The treatment of LM with imiquimod cream can be challenging due to the nature of the disease including its often large size, variegated appearance, involvement of adnexal structures, poorly defined peripheral edge and frequent localisation close to sensitive structures such as the eyes and lips, and elderly patients with multiple comorbidities. Prolonged and unpredictable inflammatory reaction and side effects and compliance with a patient-delivered therapy can also be challenging. In the literature to date, studies evaluating the use of imiquimod to treat LM have utilised varying methodologies and provided short follow-up and these limitations have impaired the development of clear guidelines for dosage and management of side effects. Based on our multidisciplinary experience and review of the literature, we propose practical clinical strategies for the use of imiquimod for treating LM, detailing optimal administration procedures in various clinical scenarios and long-term management, with the aim of facilitating optimal patient outcomes.

Lentigo Maligna

Lentigo maligna (LM) is a melanocytic neoplasm found on chronically sun-exposed areas of the body, particularly the head and neck. It commonly occurs in the elderly and has been referred to as a "senile freckle." It has also been termed "Hutchinson melanotic freckle," as it was first described by John Hutchinson in 1892. LM is defined as melanoma in situ and thus confined to the epidermis. LM lesions that invade the dermis are termed lentigo maligna melanoma, 1 of the 4 subtypes of malignant melanoma.

Systematic Review of the Role of Mohs Micrographic Surgery in the Management of Early-Stage Melanoma of the Head and Neck

BACKGROUND

The role of Mohs micrographic surgery (MMS) in the management of melanoma of the head and neck (HNM) has been controversial. The authors systematically reviewed the local recurrence rate of melanoma in situ (MIS) and T1a melanomas using MMS compared with conventional wide local excision (WLE) and staged excision (SE).

OBJECTIVE

To systematically review the local recurrence rate of early-stage melanomas of the HNM treated with MMS versus WLE or SE.

METHODS AND MATERIALS

A search of English medical literature was conducted through the common databases until November 26, 2019. Using PRISMA guidelines for the treatment of MIS and T1a melanoma with MMS, WLE, or SE, our search yielded a total of 32 articles.

RESULTS

Mohs micrographic surgery has a lower local recurrence rate for early-stage melanomas over both SE and WLE {pooled recurrence risk 0.8% (95% confidence interval [CI] 0.4-1.1) versus 2.5% (95% CI 1.5-3.4) versus 8.7% (95% CI 5.1-12.2) (p < .001), respectively}.

CONCLUSION

Mohs micrographic surgery may offer a lower recurrence rate than SE or WLE in the management of early-stage melanomas of the face or HNM. Further clinical validation in a randomized controlled trial is required.

Margins of Melanoma Excision and Modifications to Standards

Surgery with wide local excision is the mainstay of treatment for primary melanoma. Surgical margins differ depending on the depth of the primary lesion, subtype, and anatomic, cosmetic, or functional considerations. Adjuncts or alternative treatments to wide local excision are limited to specific patient populations and mainly experimental in nature.

Melanoma In Situ: A Critical Review and Re-Evaluation of Current Excision Margin Recommendations

Most international clinical guidelines recommend 5-10 mm clinical margins for excision of melanoma in situ (MIS). While the evidence supporting this is weak, these guidelines are generally consistent. However, as a result of the high incidence of subclinical extension of MIS, especially of the lentigo maligna (LM) subtype, wider margins will often be needed to achieve complete histologic clearance. In this review, we assessed all available contemporary evidence on clearance margins for MIS. No randomized trials were identified and the 31 non-randomized studies were largely retrospective reviews of single-surgeon or single-institution experiences using Mohs micrographic surgery (MMS) for LM or staged excision (SE) for treatment of MIS on the head/neck and/or LM specifically. The available data challenge the adequacy of current international guidelines as they consistently demonstrate the need for clinical margins > 5 mm and often > 10 mm. For LM, any MIS on the head/neck, and/or ≥ 3 cm in diameter, all may require wider clinical margins because of the higher likelihood of subclinical spread. Histologic clearance should be confirmed prior to undertaking complex reconstruction. However, it is not clear whether wider margins are necessary for all MIS subtypes. Indeed, it seems that this is unlikely to be the case. Until optimal surgical margins can be better defined in a randomized trial setting, ideally controlling for MIS subtype and including correlation with histologic excision margins, techniques such as preliminary border mapping of large, ill-defined lesions and, most importantly, sound clinical judgement will be needed when planning surgical clearance margins for the treatment of MIS.

Utility of teledermatopathology for intraoperative margin assessment of melanoma in situ, lentigo maligna type: A 6 year community practice experience

BACKGROUND

Achieving negative margins for melanoma in situ, lentigo maligna type can be challenging, particularly on cosmetically sensitive areas.

OBJECTIVE

To assess the utility of intraoperative frozen section margin assessment using a teledermatopathology system in the treatment of head and neck lentigo maligna.

METHODS AND MATERIALS

Over a 6 year period, 96 patients with lentigo maligna had surgical excisions. The margins were assessed intraoperatively with frozen sections prepared in the manner used in Mohs surgery. The surgeon guided the frozen section slides around the margin while a dermatopathologist assessed the margin remotely.

RESULTS

In 2/96 (2.1%) cases, the safety margin was positive (frozen sections were false negative). In 1 further case (1%) there was a recurrence of the melanoma 13 months following the excision.

CONCLUSION

The described method is effective in treating melanoma in situ, lentigo maligna type with clearance rates similar to previous studies for Mohs surgery.

Surgical Margin Mapping of Melanoma In Situ Using In Vivo Reflectance Confocal Microscopy Mosaics

BACKGROUND

Melanoma in situ (MIS) can have poorly defined borders and subclinical extension that makes margin control challenging. Reflectance confocal microscopy (RCM) is a promising noninvasive technique that can be used to assess subclinical spread.

OBJECTIVE

To optimize surgical margins of histology-proven MIS using RCM mosaics.

MATERIALS AND METHODS

Prospective review of 22 patients with histology-proven MIS who underwent RCM margin mapping prior to staged excision, between August 1, 2018, and August 13, 2020, at the Department of Dermatology, University of New Mexico, School of Medicine.

RESULTS

Twenty patients (91%) had tumor clearance on the first stage using a 3-mm surgical margin after confocal margin mapping.

CONCLUSION

Reflectance confocal microscopy margin mapping using the mosaic device tends to clear MIS in one stage, and the use of the handheld device may improve the accuracy for difficult anatomic areas. Current Procedural Terminology codes for RCM do not reflect the time required and complexity of the procedure. Reflectance confocal microscopy margin mapping prior to excision has the potential to decrease the number of stages needed for melanoma removal, reduce treatment time, and cost.

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, 2021.

Lentiginous melanoma (lentigo maligna and lentigo maligna melanoma) in Australia: clinicopathological characteristics, management and recurrence rates after 10-year follow-up at a tertiary centre

BACKGROUND

Lentiginous melanoma or lentigo maligna is a slow-growing type of melanoma frequently arising in sun-damaged skin and often first diagnosed in the elderly. Few studies report long-term follow-up.

OBJECTIVES

To define characteristics of lentiginous melanoma in situ (LM) and invasive lentiginous melanoma (LMM) in Australian patients managed at a tertiary centre and describe local recurrence or treatment failure rates after long-term follow-up.

METHODS

Retrospective single-centre study of LM/LMM patients evaluated between January 2005 and March 2007. Medical and photographic records were reviewed.

RESULTS

One hundred two patients were included, with a total of 117 lesions (70 LM and 47 LMM). Seventy-nine were new primary LM/LMM, and 38 were recurrences. Primary cases were mostly pigmented (71%), while 77% of recurrent cases were partially pigmented/light brown or amelanotic. The margins were clinically ill-defined in the majority of cases (64% of primary cases and 94% of recurrent cases). Dermoscopy of the primary LM/LMM showed either classic 'common' melanoma features (33%) or classic LM/LMM features (41%), while 95% of recurrent cases had no features for melanoma or LM/LMM. Primary cases that were initially excised (113, 97%) had mean histopathological clear margins of 4.9 mm (range 0.1-22 mm). The median follow-up time was 7.5 years (95% CI 5.2-10.0) with more than 10-year follow-up in 32% and 5-10 years in 24% of patients. There were 44 (38%) recurrences over the entire follow-up period. Half of the patients who recurred did so within the first 3.8 years after the first treatment.

CONCLUSION

LM/LMM often recur late and are clinically subtle; therefore, careful monitoring and long-term follow-up are required.

Nail Surgery: Six Essential Techniques

Successful nail surgery requires an understanding of specific disease processes, the anatomy of the nail unit, and fluency with only a few key techniques. This article focuses on 6 high-yield procedures, facility with which will allow the clinician to approach most of the clinical scenarios requiring surgical intervention. These encompass surgical approaches to inflammatory nail diseases, melanonychia, erythronychia, and nail melanoma in situ.