The rule of 10s versus the rule of 2s: High complication rates after conventional excision with postoperative margin assessment of specialty site versus trunk and proximal extremity melanomas

Risk factors associated with tumor upstaging in melanomas treated with Mohs micrographic surgery with melanocytic immunohistochemistry

Background

Mohs micrographic surgery with melanocytic immunohistochemistry (MMS-I) is increasingly utilized for special site melanoma treatment. Yet, frequency and risk factors associated with upstaging of all-stage cutaneous melanomas treated with MMS-I remain undefined.

Objective

Determine upstaging frequency and factors associated with tumor upstaging for all-stage melanomas treated with MMS-I.

Methods

In this retrospective, single-center case series, all cases of invasive and in situ melanoma treated with MMS-I between 2008 and 2018 were reviewed. Patient and tumor characteristics were recorded and compared between tumors that were and were not upstaged from their initial T stage.

Results

Of the 962 melanoma MMS-I cases identified, 44 (4.6%) were upstaged, including 5.6% of in situ and 2.5% of invasive tumors. Risk factors for upstaging included lack of excisional intent at the time of initial biopsy (P < .01), nonlentigo maligna subtype (P = .03), female sex (P = .02), and initial in situ diagnosis (P = .03). Nonstatistically significant characteristics evaluated included patient age (P = .97), initial Breslow depth (P = .18), and biopsy type (P = .24).

Limitations

Retrospective study design.

Conclusions

All-stage cutaneous melanomas treated with MMS-I are associated with low upstaging rates. Tumor upstaging is associated with lack of excisional intent, female sex, and in situ tumors.

Wound Healing Complications Associated with Staged Reconstruction after Facial Lentigo Maligna Resection

Background: The rates and risk factors for wound complications following staged reconstruction after facial lentigo maligna (LM) resection have not been well described. Objectives: (1) To identify the rate and types of wound complications, including infection, graft necrosis, distal flap necrosis, hematoma, superficial epidermolysis, and seroma among patients undergoing staged reconstruction after resection of LM as documented in the surgeon's clinical notes within 30 days of the procedure. (2) To determine a threshold defect size that may predict the development of wound complications. Design and Outcomes: Retrospective review at an academic medical center of patients who underwent staged reconstruction after facial LM resection over a 5-year period. Results: Ninety-eight patients were identified with a mean age of 69.2 ± 13.6 years; 37% of patients were female. The most common defect sites were the cheek (n = 41; 42%) and nose (n = 22; 22%). Twenty-five of 98 patients (26%) demonstrated complications, with the most common being wound infection (36%) and graft necrosis (24%). Those receiving perioperative antibiotics had lower rates of complication (odds ratio [OR]: 0.36; 95% confidence interval [CI]: 0.13,0.96; p = 0.041). Defects greater than 2.7 cm in maximal diameter had the highest sensitivity for predicting complications. Conclusions: Patients undergoing staged reconstruction after facial LM resection have a high rate of wound complication (26%) and defect size > 2.7 cm may be an important risk factor.

Aggregation-induced emission photosensitizer microneedles for enhanced melanoma photodynamic therapy

The incidence and mortality rates of skin melanoma have been increasing annually. Photodynamic therapy (PDT) enables effective destruction of tumor cells while minimizing harm to normal cells. However, traditional photosensitizers (PSs) suffer from photobleaching, photodegradation and the aggregation-caused quenching (ACQ) effect, and it is challenging for light to reach the deep layers of the skin to maximize the efficacy of PSs. Herein, we developed dissolving microneedles (MNs) loaded with PSs of TPE-EPy@CB[7] through supramolecular assembly. The PSs effectively enhanced the type-I reactive oxygen species (ROS) generation capacity, with a concentration of 2 μM possessing nearly half of the tumor cell-killing ability under 10 min white light irradiation. The MNs were successfully pierced into the targeted site for precise drug delivery. Additionally, the conical structure of the MNs, as well as the lens-like structure after dissolution, facilitated the transmission of light in the subcutaneous tissue, achieving significant inhibition of tumor growth with a tumor suppression rate of 97.8% and no systemic toxicity or side effects in melanoma mice. The results demonstrated the potent melanoma inhibition and biosafety of this treatment approach, exhibiting a new and promising strategy to conquer malignant melanoma.

Top 100 Most Cited Articles in Mohs Micrographic Surgery: A Bibliometric Analysis

BACKGROUND

Bibliometric analysis is a scientific method that can derive insights into major publications' trends within a field. Currently, no bibliometric study has been conducted for Mohs micrographic surgery (MMS).

OBJECTIVE

To characterize the most frequently cited articles in MMS.

METHODS

Web of Science was used to identify the 100 most cited publications on MMS between 1970 and 2022. Articles were analyzed by title, authorship, institution, journal, year, citation frequency, originating country, funding, citation index, Altmetric score, impact factor, Eigenfactor score, and article influence score.

RESULTS

Since January 2023, the top 100 articles had 9,096 total citations, ranging from 47 to 304. The top cited publication was "Mohs surgery is the treatment of choice for recurrent (previously treated) basal-cell carcinoma" in 1989. The top contributing organization was Harvard University (17%) and top contributing authors were Brodland, DJ (12%) and Zitelli, JA (11%). The year 2005 accounted for most of the articles (12%). Most articles were from the Journal of the American Academy of Dermatology (32%) and Dermatologic Surgery (27%). The United States contributed to 76% of the top articles.

CONCLUSION

This bibliometric analysis offers researchers a detailed overview of important MMS publications and provides useful data into current findings steering MMS research and practice.

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.

Perifollicular linear projections: A dermatoscopic criterion for the diagnosis of lentigo maligna on the face

BACKGROUND

Lentigo maligna (LM) can mimic benign, flat, pigmented lesions and can be challenging to diagnose.

OBJECTIVE

To describe a new dermatoscopic feature termed "perifollicular linear projections (PLP)" as a diagnostic criterion for LM on the face.

METHODS

Retrospective study on reflectance confocal microscopy and dermatoscopy images of flat facial pigmented lesions originating from 2 databases. PLP were defined as short, linear, pigmented projections emanating from hair follicles. Dermatoscopy readers were blinded to the final histopathologic diagnosis.

RESULTS

From 83 consecutive LMs, 21/83 (25.3%) displayed "bulging of hair follicles" on reflectance confocal microscopy and 18 of these 21 (85.7%), displayed PLP on dermatoscopy. From a database of 2873 consecutively imaged and biopsied lesions, 252 flat-pigmented facial lesions were included. PLP was seen in 47/76 melanomas (61.8%), compared with 7/176 lesions (3.9%) with other diagnosis (P < .001). The sensitivity was 61.8% (95% CI, 49.9%-72.7%), specificity 96.0% (95% CI, 92.9%-98.4%). PLP was independently associated with LM diagnosis on multivariate analysis (OR 26.1 [95% CI, 9.6%-71.0]).

LIMITATIONS

Retrospective study.

CONCLUSION

PLP is a newly described dermatoscopic criterion that may add specificity and sensitivity to the early diagnosis of LM located on the face. We postulate that PLP constitutes an intermediary step in the LM progression model.

The Controversy and Value of Mohs Micrographic Surgery for Melanoma and Melanoma in Situ on the Trunk and Extremities

BACKGROUND

The use of Mohs surgery for melanoma on the trunk and extremities is not supported in the guidelines of dermatology, but is widely used in the real world.

OBJECTIVE

The purpose of this article is to expose the value of Mohs surgery for melanoma on the trunk and extremities for consideration of updating the guidelines.

MATERIALS AND METHODS

This was a retrospective review of a prospectively maintained database 7 to identify patients whose melanomas would likely have recurred using standard surgical margins. A prediction model was used to evaluate the value of Mohs surgery.

RESULTS

The model predicted that 2,847 (2%) patients with melanoma on the trunk and extremities would likely recur each year with standard surgical margins even after re-excision when positive margins were identified, compared with 0.1% after Mohs surgery. This likely would result in the upstaging of 27% of melanoma in situ patients and 13% of patients with invasive melanoma. The upstaging would also result in a decrease in melanoma-specific survival and the death of 1% of patients with true local recurrences of melanoma.

CONCLUSION

Mohs surgery has value for melanoma on the trunk and extremities by minimizing local recurrence and death from disease progression.

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.

Association of Excision Margin Size With Local Recurrence and Survival in Patients With T1a Melanoma at Critical Structures

Importance

Melanoma guidelines recommend surgical excision with 10-mm margins for T1 melanoma. However, this procedure may be problematic at sites close to critical structures such as the scalp, face, external genitalia, acral, periumbilical, and perineal areas.

Objective

To compare outcomes of wide (10-mm margins) vs narrow (5-mm margins) excision in patients with T1a melanoma near critical structures.

Design, Setting, and Participants

This cohort study was a retrospective comparison of 1341 consecutive patients aged 18 years or older from the National Cancer Institute of Milan, Italy, diagnosed between 2001 and 2020 with T1a cutaneous melanoma close to critical structures who accepted wide excision vs narrow excision.

Exposures

Local recurrence and melanoma-specific mortality (MSM) rates with 5-mm vs 10-mm excision margins.

Main Outcomes and Measures

The primary aim of the study was to ascertain whether a narrower (5-mm) vs wider (10-mm) excision margin was associated with local recurrence and MSM. The secondary aim was to compare the need for reconstructive surgery in the groups defined by excision margin width. Between April 28 and August 7, 2022, associations were assessed by weighted Cox and Fine-Gray univariable and multivariable models.

Results

A total of 1179 patients met the inclusion criteria (median [IQR] age, 50.0 [39.5-63.0] years; female, 610 [51.7%]; male, 569 [49.3%]). Six hundred twenty-six patients (53.1%) received a wide excision (434 [69.3%] with linear repair and 192 [30.7%] with flap or graft reconstruction) and 553 (46.9%) received a narrow excision (491 [88.8%] with linear repair and 62 [11.2%] with flap or graft reconstruction). The weighted 10-year MSM was 1.8% (95% CI, 0.8%-4.2%) in the wide group and 4.2% (95% CI, 2.2%-7.9%) in the narrow group; the weighted 10-year local recurrence rate was 5.7% (95% CI, 3.9%-8.3%) in the wide group and 6.7% (95% CI, 4.7%-9.5%) in the narrow group. Breslow thickness greater than 0.4 mm (subdistribution hazard ratio [sHR] for 0.6 vs 0.4 mm, 2.42; 95% CI, 1.59-3.68; P < .001) and mitotic rate greater than 1/mm2 (sHR for a single increment, 3.35; 95% CI, 2.59-4.32; P < .001) were associated with worse MSM. Multivariable analysis showed that acral lentiginous melanoma, lentigo maligna melanoma, and increasing Breslow thickness were associated with a higher incidence of local recurrence.

Conclusions and Relevance

The study's findings suggest that local excision with 5-mm margins for T1a melanoma may not be associated with an increased risk of local recurrence. Breslow thickness greater than 0.4 mm, mitotic rate greater than 1/mm2, and acral lentiginous melanoma and lentigo maligna melanoma subtypes were associated with a higher risk of recurrence. These findings may be useful for future melanoma treatment guidelines.

[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.

Factors Associated With Upstaging of Melanoma Thickness on Final Excision

INTRODUCTION

The incidence and risk factors associated with upstaging from initial biopsy to definitive excision in cutaneous melanoma have not been established. The aim of this study was to determine the incidence of tumor stage upstaging and associated risk factors using the National Cancer Database.

METHODS

A retrospective study of the National Cancer Database between 2012 and 2016 was performed. The cohort of patients undergoing excision of melanoma with available data comprised 133,592 patients. Differences in characteristics for upstaging were determined using Wilcox rank-sum, chi-square, or Fisher's exact tests. Multivariable analysis was performed using logistic regression to determine factors associated with upstaging.

RESULTS

Incidence of upstaging was 5.2%. Upstaged patients were older, male, of non-White race, and of lower education level (P < 0.001). Lesions of the head/neck and lower extremity had increased incidence of upstaging compared to the trunk (P < 0.001). Nodular and acral lentiginous melanoma was associated with higher incidence of upstaging compared to superficial spreading melanoma (P < 0.001). Patients with lymphovascular invasion had increased risk of upstaging (P < 0.001).

CONCLUSIONS

Upstaging of melanoma is infrequent but is significantly more prevalent in non-White patients and those with lower educational status. Provider and patient education should include the higher risk of upstaging in these groups and the possible need for further surgical intervention, such as re-excision of margins and sentinel lymph node biopsy.

Local Recurrence Rates After Excision of Desmoplastic Melanoma: A Systematic Review and Meta-Analysis

BACKGROUND

Few prospective studies have evaluated local recurrence rates (LRR) after excision of desmoplastic melanoma (DM); however, several retrospective studies have reported high LRR.

OBJECTIVE

To determine LRR after excision of DM and evaluate factors affecting LRR.

MATERIALS AND METHODS

Systematic review of the PubMed, Embase, and Web of Science databases was performed to identify studies reporting local recurrence after excision of DM with conventional wide local excision (WLE), Mohs micrographic surgery (MMS), or staged excision (SE). Meta-analysis was performed to calculate summary LRR and pooled risk ratios (RR).

RESULTS

Literature search identified 4 studies evaluating MMS or SE (total n = 61 DM). 53 studies assessed WLE ( n = 3,080) and were analyzed quantitatively. The overall LRR after WLE of DM was 21% (95% CI, 0.16-0.28; n = 2,308). Local recurrence rate was higher with positive/unknown histologic excision margins (49%, 95% CI, 0.25-0.74; n = 91) versus negative histologic margins (11%, 95% CI, 0.07-0.17; n = 1,075; [ p < .01]). Neurotropism was also associated with increased LRR (RR, 1.79; 95% CI, 1.34-2.38, p < .01; n = 644).

CONCLUSION

DM has high LRR after WLE. Local recurrence risk was greatest with positive excision margins, indicating the importance of achieving negative microscopic margins. Greater study of MMS and SE for DM is required.

A Cost Comparison Between Mohs Micrographic Surgery and Conventional Excision for the Treatment of Head and Neck Melanomas In Situ and Thin Melanomas

BACKGROUND

Variation in operative setting and surgical technique exists when treating specialty site melanomas. There are limited data comparing costs among surgical modalities.

OBJECTIVE

To evaluate the costs of head and neck melanoma surgery performed with Mohs micrographic surgery or conventional excision in the operating room or office-based settings.

METHODS

A retrospective cohort study was performed on patients aged 18 years and older with surgically treated head and neck melanoma in 2 cohorts, an institutional cohort and an insurance claims cohort, for the years 2008-2019. The primary outcome was total cost of care for a surgical encounter, provided in the form of insurance reimbursement data. A generalized linear model was used to adjust for covariates affecting differences between treatment groups.

RESULTS

In the institutional and insurance claims cohorts, average adjusted treatment cost was highest in the conventional excision-operating room treatment group, followed by the Mohs surgery and conventional excision-office setting (p < .001).

CONCLUSION

These data demonstrate the important economic role the office-based setting has for head and neck melanoma surgery. This study allows cutaneous oncologic surgeons to better understand the costs of care involved in head and neck melanoma treatment. Cost awareness is important for shared decision-making discussions with patients.

Assessing Rates of Positive Surgical Margins After Standard Excision of Vulvar Melanomas

BACKGROUND

Vulvar melanoma is a rare malignancy with frequent recurrence and poor prognosis. National guidelines recommend wide local excision of these tumors with allowances for narrower margins for anatomic and functional limitations, which are common on specialty sites. There is presently a lack of data of margin positivity after standard excision of vulvar melanomas.

OBJECTIVE

We aim to evaluate the rate of positive margins after standard excision of vulvar melanomas.

MATERIALS AND METHODS

Retrospective cohort study of surgically excised vulvar melanomas from the NCDB diagnosed from 2004 to 2019.

RESULTS

We identified a total of 2,226 cases. Across surgical approaches and tumor stages, 17.2% (Standard Error [SE]: 0.8%) of cases had positive surgical margins. Among tumor stages, T4 tumors were most commonly excised with positive margins (22.9%, SE: 1.5%). On multivariable survival analysis, excision with positive margins was associated with significantly poorer survival (Hazard Ratio 1.299, p = .015).

CONCLUSION

We find that positive margin rates after standard excision of vulvar malignancies are higher than for other specialty site melanomas. Our data suggest that use of surgical approaches with complete margin assessment may improve local control and functional outcomes for patients with vulvar melanoma as they have for patients with other specialty site melanomas.

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.

Permanent section margin concordance after Mohs micrographic surgery with immunohistochemistry for invasive melanoma and melanoma in situ: A retrospective dual-center analysis

BACKGROUND

Mohs micrographic surgery (MMS) for melanoma practices vary among dermatologic surgeons. The implementation of immunohistochemical staining in MMS for melanoma mitigates challenges associated with slide interpretation; however, the reliability of melanoma antigen recognized by T cells 1 (MART-1), the preferred immunostain for melanoma, has yet to be compared with permanent section pathology.

OBJECTIVE

To assess concordance rates of MART-1 frozen sections and permanent section pathologic interpretation of melanoma treated with MMS.

METHODS

A dual-center retrospective analysis was conducted to collect concordance and demographic data. Chi-square tests were performed for group comparisons of categorical variables.

RESULTS

Of the 379 permanent sections sent, 367 were concordant with frozen section pathology for an overall concordance rate of 96.8%. Cases were stratified into indeterminately concordant and indisputably concordant. Twenty-two (6%) of cases were indeterminately concordant, whereas 345 (94.0%) of cases were indisputably concordant.

LIMITATIONS

The concordance rate is derived from a comparison of adjacent tissue margins, an inevitable consequence of utilizing 2 techniques.

CONCLUSION

To the author's knowledge, this study represents the largest investigation examining concordance rates of MART-1 frozen sections in Mohs for melanoma. High concordance disputes the ongoing need for additional permanent margins when using MART-1 in routine cases.

3D printed heterogeneous hybrid hydrogel scaffolds for sequential tumor photothermal-chemotherapy and wound healing

Surgical resection remains the mainstay of melanoma treatment. However, due to the difficulties in controlling tumor recurrence and wound healing simultaneously, high postoperative recurrence rates and wound reconstruction remain the most significant challenges. As a result, a heterogeneous hybrid hydrogel scaffold was designed in this work to achieve sequential photothermal therapy and chemotherapy for melanoma recurrence inhibition and wound healing. A 3D printing platform was used to create a SA-GG@PDA hybrid hydrogel scaffold, which was prepared from a hybrid bioink consisting of sodium alginate (SA), gellan gum (GG), and polydopamine nanoparticles (PDA NPs). The printability, biocompatibility, and mechanical qualities of the hybrid bioink were all satisfactory. PDA NPs were generated in situ in the hybrid bioink, providing superior photothermal effects to the scaffold. After coating with a thermosensitive gelatin hydrogel loaded with the chemotherapeutic drug doxorubicin (DOX), the heterogeneous hydrogel scaffold could accelerate drug release under photothermal triggering and achieve photothermal-chemotherapy to suppress tumor cell proliferation and recurrence after surgical resection. Subsequently, the printed porous hybrid hydrogel scaffold enhanced HUVEC proliferation and migration, as well as tissue ingrowth, promoting wound healing following surgery. In the same mouse model, the sequential treatment with the heterogeneous SA-GG@PDA + DOX hydrogel scaffold was tested. The fabrication of the heterogeneous SA-GG@PDA + DOX hydrogel scaffold with multifunctional capabilities seemed to be a potential technique for preventing tumor recurrence and promoting wound healing following surgery.

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.

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.

A Call for Evidence-Based Conservative Management of Nail Unit Malignancies

SUMMARY

Nail unit squamous cell carcinoma and melanoma are the most common malignancies of the nail apparatus. Compared to their cutaneous counterparts, they are diagnosed later and perceived as more aggressive. This may result in overzealous management, including radiographic imaging with poor sensitivity and specificity, interventional nodal staging by sentinel lymph node biopsy, amputation over digit-sparing tumor resections, and elaborate reconstructions after tumor extirpation. In this review article, the authors evaluate the evidence behind several misconceptions in nail malignancy management and provide evidence-based guidance for more conservative care.

Systematic Review of Technical Variations for Mohs Micrographic Surgery for Melanoma

BACKGROUND

Mohs micrographic surgery (MMS) for cutaneous melanoma is becoming more prevalent, but surgical technique varies.

OBJECTIVE

To define variations in published techniques for MMS for melanoma.

METHODS AND MATERIALS

A systematic review was performed of PubMed, EMBASE, and Scopus databases to identify all articles describing surgical techniques for MMS for melanoma. Technical details were recorded for the preoperative, intraoperative, and postoperative phases of MMS.

RESULTS

Twenty-four articles were included. Mohs surgeons vary in how they assess clinical margins, how wide a margin they excise on the first MMS layer, and how they process tissue to determine tumor stage and margin clearance during MMS for melanoma.

CONCLUSION

Mohs micrographic surgery for melanoma is performed with varied surgical techniques. To establish best practices, additional research is necessary to determine how different techniques affect outcomes.

Slow Mohs Micrographic Surgery for Acral Melanoma Treatment in Korean Patients

BACKGROUND

Obtaining conventional wide surgical margins is challenging in melanomas occurring at anatomically complex sites (e.g., hands and feet).

OBJECTIVE

We investigated the potential benefits of slow Mohs micrographic surgery (MMS) for acral melanomas.

MATERIALS AND METHODS

This single-center retrospective study investigated 210 patients who underwent slow MMS (n = 66) or wide local excision (WLE, n = 144) for melanomas during 2005 to 2015. Slow MMS was used for melanomas in anatomically complex locations and for high-risk lesions.

RESULTS

Acral melanoma (166/210) was the most common lesion observed in patients, in addition to head and neck (21/210) and trunk (23/210) melanomas. Slow MMS was more commonly performed for acral, and head and neck melanomas (32.5% and 52.4%, respectively) than for trunk melanomas (4.3%, p = .002). Local recurrence of acral melanomas occurred in 3.7% of patients after slow MMS and in 10.7% of patients after WLE. Multivariate analysis showed comparable prognostic outcomes between slow MMS and WLE used for acral melanomas. Compared with WLE, slow MMS resulted in a smaller postoperative defect after acral lesion excision (p < .001).

CONCLUSION

Slow MMS is an effective alternative to WLE for acral melanomas in anatomically complex sites, as evidenced by superior outcomes and maximum tissue conservation.

Association of Mohs Micrographic Surgery vs Wide Local Excision With Overall Survival Outcomes for Patients With Melanoma of the Trunk and Extremities

Importance

Although previous database studies suggest that Mohs micrographic surgery (MMS) treatment is associated with improved overall survival (OS) for head and neck melanomas, outcomes for trunk and extremity (T&E) tumors have not been adequately evaluated.

Objective

To assess survival outcomes for patients with melanomas of the T&E treated with MMS vs wide local excision (WLE).

Design, Setting, and Participants

This retrospective cohort study examined deidentified data from the National Cancer Database between 2004 and 2015. Inclusion criteria for the analysis included diagnosis of trunk, upper extremity, or lower extremity melanoma; known Breslow depth; removal by MMS or WLE; and known last date of survival status.

Main Outcomes and Measures

Five-year all-cause mortality (ACM) rates.

Results

A total of 188 862 in situ and invasive melanomas were included in the analysis (MMS, 2.3%; WLE, 97.7%); the mean (SD) age of patients included was 58.8 (16.0) years, and 52.7% were male. Multivariate analysis demonstrated no OS difference among trunk (WLE hazard ratio [HR], 1.097; 95% CI, 0.950-1.267; P = .21), upper extremity (WLE HR, 1.013; 95% CI, 0.872-1.176; P = .87), lower extremity (WLE HR, 0.934; 95% CI, 0.770-1.134; P = .49), or combined T&E (WLE HR, 1.031; 95% CI, 0.941-1.130; P = .51) tumors. Factors associated with increased risk of ACM on multivariate analysis of all tumors included increasing age (HR, 1.043; 95% CI, 1.042-1.044; P < .001), no insurance or nonprivate insurance (none: HR, 1.921 [95% CI, 1.782-2.071]; Medicaid: HR, 2.410 [95% CI, 2.242-2.591]; Medicare: HR, 1.237 [95% CI, 1.194-1.281]; other government insurance: HR, 1.279 [95% CI, 1.117-1.465]; P < .001 for all), positive surgical margins (HR, 1.609; 95% CI, 1.512-1.712; P < .001), a Charlson-Deyo comorbidity score greater than 0 (Charlson-Deyo score of 1: HR, 1.340; 95% CI, 1.295-1.385; P < .001; Charlson-Deyo score of ≥2: HR, 2.044; 95% CI, 1.934-2.159; P < .001), tumor ulceration (HR, 2.175; 95% CI, 2.114-2.238; P < .001), and increasing Breslow depth (HR, 1.002 [per 0.1 mm]; P < .001). Female sex (HR, 0.698; 95% CI, 0.680-0.716; P < .001) and nonnodular subtype (lentigo maligna/lentigo maligna melanoma: HR, 0.743; 95% CI, 0.686-0.805; P < .001; superficial spreading: HR, 0.739; 95% CI, 0.710-0.769; P < .001; other subtype: HR, 0.817; 95% CI, 0.790-0.845; P < .001; nodular: HR, 1 [reference]) were associated with improved OS.

Conclusions and Relevance

This cohort study of patients surgically treated for melanomas of the trunk and/or extremities found that, compared with WLE, MMS was not associated with significantly different OS for T&E melanomas.

Clinical size is a poor predictor of invasion in melanoma of the lentigo maligna type

BACKGROUND

There are no well-defined clinical factors to predict the risk of occult invasion in melanoma of the lentigo maligna type (LM) before complete histopathologic analysis.

OBJECTIVE

To evaluate whether clinical size was a predictor of invasion in LM and subclinical extension.

METHODS

Consecutive cases of LM were recorded in a prospectively maintained database from 2006 to 2019. Patient and tumor data were recorded during initial evaluation. The LM clinical area was calculated in square millimeters (length × width). All patients were treated with staged excision.

RESULTS

We included 600 patients. The mean age was 65.9 years (standard deviation, 12.3; range, 27-95 years); 62.8% (n = 377) were men. The mean LM clinical area was 128.32 mm² for in situ lesions versus 200.14 mm for invasive lesions (P = .1). Based on quantile regression, the median margin required for complete removal increased with LM clinical area.

LIMITATIONS

The study was performed in a tertiary cancer center with possible referral bias and more complex cases.

CONCLUSIONS

LM can present with variable clinical size, which may correlate with subclinical extension; however, the presence of invasion is not well estimated by LM clinical area.

Incompletely excised lentigo maligna melanoma is associated with unpredictable residual disease: clinical features and the emerging role of reflectance confocal microscopy

BACKGROUND

Lentigo maligna/lentigo maligna melanoma (LM/LMM) poses a treatment and surgical challenge given unpredictable subclinical extension resulting in incomplete excision.

OBJECTIVES

To describe the demographic, clinical and pathologic characteristics of incompletely excised LM/LMM. To evaluate the potential role of reflectance confocal microscopy (RCM).

PATIENTS AND METHODS

A retrospective review of a melanoma database at a tertiary cancer centre for patients referred with 'incompletely excised LM/LMM' or 'incompletely excised melanoma' between October 2006 and July 2017. We recorded clinical and pathological data and surgical margins needed to clear the residual LM/LMM. The second part consisted of a prospective cohort of patients in which RCM was performed when presenting with incompletely excised LM/LMM.

RESULTS

We included a total of 67 patients (retrospective + prospective cohort); mean age was 64.9 (standard deviation: 11.3) years and 52.2% were males. For the retrospective cohort (n = 53), the mean scar size was 3.4 cm. The average initial margins excised prior to presentation were 4.8 mm (range 3-7 mm). The average additional margin needed to clear the residual, incompletely excised LM/LMM was 7.8 mm. For the prospective cohort (n = 14), there were no differences in age, gender or size when compared to the retrospective cohort. RCM had a diagnostic accuracy of 78.6%, a sensitivity of 90.9%, a specificity of 33.3% and a positive predictive value of 83.3% for the detection of incompletely excised LM/LMM.

CONCLUSIONS

Incompletely excised LM/LMM is a poorly characterized clinical-pathological scenario that may require considerable extra margins for microscopic clearance. RCM may emerge as a valuable tool for the evaluation of patients with incompletely excised LM/LMM.