Conventional histology vs. three-dimensional histology in lentigo maligna melanoma

Review on the Role of Paraffin-embedded Margin-controlled Mohs Micrographic Surgery to Treat Skin Tumors

Paraffin-embedded margin-controlled Mohs micrographic surgery (PMMS) includes various procedures such as slow Mohs or deferred Mohs technique, the Muffin and Tübingen techniques, and staged margin excision, or the spaghetti technique. PMMS is a variation of conventional Mohs micrographic surgery (MMS) that allows histopathological examination with delayed margin control. PMMS requires minimum training and may be adopted by any hospital. The setback is that PMMS can require procedures across multiple days. PMMS lowers the rate of recurrence of basal cell carcinoma vs wide local excision in high-risk basal cell carcinoma, and improves the rates of recurrence and survival in lentigo maligna. PMMS can be very useful in high-risk squamous cell carcinoma treatment. Finally, it is a promising technique to treat infrequent skin neoplasms, such as dermatofibrosarcoma protuberans, or extramammary Paget's disease, among others. In this article, we present a literature narrative review on PMMS, describing techniques and indications, and highlighting long-term outcomes.

Review on the Role of Paraffin-embedded Margin-controlled Mohs Micrographic Surgery to Treat Skin Tumors

Paraffin-embedded margin-controlled Mohs micrographic surgery (PMMS) includes various procedures such as slow Mohs or deferred Mohs technique, the Muffin and Tübingen techniques, and staged margin excision, or the spaghetti technique. PMMS is a variation of conventional Mohs micrographic surgery (MMS) that allows histopathological examination with delayed margin control. PMMS requires minimum training and may be adopted by any hospital. The setback is that PMMS can require procedures across multiple days. PMMS lowers the rate of recurrence of basal cell carcinoma vs wide local excision in high-risk basal cell carcinoma, and improves the rates of recurrence and survival in lentigo maligna. PMMS can be very useful in high-risk squamous cell carcinoma treatment. Finally, it is a promising technique to treat infrequent skin neoplasms, such as dermatofibrosarcoma protuberans, or extramammary Paget's disease, among others. In this article, we present a literature narrative review on PMMS, describing techniques and indications, and highlighting long-term outcomes.

Sentinel lymph node biopsy for lentigo maligna melanoma under local anaesthesia

BACKGROUND

Lentigo maligna melanoma is mainly localized in the head and neck region in elderly patients. Due to its slow horizontal growth, it has a good prognosis compared to other melanoma subtypes, but specific data are rare.

OBJECTIVES

The aim of this study was to investigate sentinel lymph node biopsy in lentigo maligna melanoma under local anaesthesia and to discuss the benefit.

METHODS

Investigation of patients with lentigo maligna melanoma and tumour thickness ≥1 mm treated at the Department of Dermatology, University Medical Centre Tuebingen, between January 2008 and October 2019.

RESULTS

In total, 204 patients (126 SLNB, 78 non-SLNB) with a median age of 75.7 years (SLNB: 73.3 years, non-SLNB: 79.7 years) could be included. Sixteen of 126 (12.7%) sentinel lymph nodes were positive. Five-year overall survival was 87.9% (88.5% SLNB; 87.4% non-SLNB) and 5-year distant metastasis-free survival was 85.8% (85.4% SLNB; 86.7% non-SLNB). There was no significant difference for distant metastasis-free survival (p = 0.861) and overall survival (p = 0.247) between patients with and without sentinel lymph node biopsy.

CONCLUSIONS

Sentinel lymph node biopsy in lentigo maligna melanoma under local anaesthesia is a safe and simple method, even in very old patients. However, LMM has a very good 5-year overall survival. In high-risk patients with high tumour thickness and/or ulceration, adjuvant immunotherapy can now be offered without the need to perform this procedure.

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.

Topical Treatment of Melanoma In Situ, Lentigo Maligna, and Lentigo Maligna Melanoma with Imiquimod Cream: A Systematic Review of the Literature

INTRODUCTION

The classical management of melanoma is surgery, but this can be challenging because of several factors, such as age, body area, lesion size, among others. Topical imiquimod may be a therapeutic option for the treatment of melanoma in situ and lentigo maligna melanoma due to its efficacy, tolerability, and non-invasiveness. The purpose of this systematic review is to assemble current evidence on the treatment of non-metastatic melanoma with topical imiquimod.

METHODS

The PubMed/MEDLINE and Cochrane Library databases were searched as the primary sources using the main search terms "imiquimod" combined with "lentigo maligna" and "melanoma" with the command "AND." Articles were identified, screened, and extracted for relevant data, following the PRISMA guidelines.

RESULTS

A total of 87 studies covering 1803 lesions treated with imiquimod cream were identified and included in this sytematic review. Forty-nine studies were case reports, 16 were retrospective analyses, 3 were open label trials, six were case series; one study was a controlled randomized trial, one was a randomized trial, and one was a single-arm phase III trial. Because of the high number of low-evidence studies, the overall risk of bias resulted high. In 55 studies, imiquimod 5% was used in monotherapy as the primary treatment; only in one study was imiquimod 3.75% introduced. In most cases, the topical treatment was applied once daily, with the exception of nine cases where an increased daily dosage was prescribed. The total duration of the treatment regimen was extremely variable and depended on body area and tolerability, with differences among patients of the same study. In six studies, imiquimod was used as neoadjuvant therapy before the surgical excision, and in 11 studies it was used after surgery as complementary or adjuvant therapy. In total, 1133 of the 1803 (62.8%) lesions were reported to be cleared after the treatment, taking into account that not all of the patients completed the treatment. Of these 1133 lesions, histological clearance was achieved in 645 (56.9%) lesions and clinical clearance only was achieved in 490 (43.2%) lesions; relapse occurred in 107 lesions.

CONCLUSIONS

The heterogeneity of the studies included in this systematic review precludes the drawing of any relevant conclusions regarding the application of imiquimod. Its efficacy in melanoma in situ and lentigo maligna melanoma has been demonstrated, but further evidence from controlled studies concerning the modalities is missing.

[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.

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): 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.

European consensus-based interdisciplinary guideline for melanoma. Part 2: Treatment - Update 2022

A unique collaboration of multidisciplinary experts from the European Dermatology Forum (EDF), the European Association of Dermato-Oncology (EADO), and the European Organization of Research and Treatment of Cancer (EORTC) was formed to make recommendations on cutaneous melanoma diagnosis and treatment, based on the systematic literature reviews and the experts' experience. Cutaneous melanomas are excised with one to 2-cm safety margins. Sentinel lymph node dissection shall be performed as a staging procedure in patients with tumor thickness ≥1.0 mm or ≥0.8 mm with additional histological risk factors, although there is as yet no clear survival benefit for this approach. Therapeutic decisions in stage III/IV patients should be primarily made by an interdisciplinary oncology team ("tumor board"). Adjuvant therapies can be proposed in stage III/completely resected stage IV patients and are primarily anti-PD-1, independent of mutational status, or alternatively dabrafenib plus trametinib for BRAF mutant patients. In distant metastases (stage IV), either resected or not, systemic treatment is always indicated. For first-line treatment particularly in BRAF wild-type patients, immunotherapy with PD-1 antibodies alone or in combination with CTLA-4 antibodies shall be considered. In stage IV melanoma with a BRAF-V600  E/K mutation, first-line therapy with BRAF/MEK inhibitors can be offered as an alternative to immunotherapy. In patients with primary resistance to immunotherapy and harboring a BRAF-V600  E/K mutation, this therapy shall be offered as second-line therapy. Systemic therapy in stage III/IV melanoma is a rapidly changing landscape, and it is likely that these recommendations may change in the near future.

Local Recurrence of Melanoma Is Higher After Wide Local Excision Versus Mohs Micrographic Surgery or Staged Excision: A Systematic Review and Meta-analysis

BACKGROUND

Complete removal of melanoma is a primary goal of excision, and local recurrence is one measure to evaluate the efficacy of surgical technique.

OBJECTIVE

To compare published local recurrence rates for melanoma treated with Mohs micrographic surgery (MMS) or staged excision versus wide local excision (WLE).

METHODS AND MATERIALS

Search of 6 databases identified comparative and noncomparative studies that reported local recurrence rates after MMS, staged excision, or WLE for melanoma. Random-effects meta-analysis was used to estimate odds ratios and 95% confidence interval (CI) from comparative studies and event rates from noncomparative studies.

RESULTS

Of the 71 studies included (16,575 patients), 12 were comparative studies (2,683 patients) and 56 were noncomparative studies (13,698 patients). Comparative studies showed increased recurrence after WLE compared with MMS or staged excision (odds ratio [OR], 2.5; 95% CI, 1.4-4.6) and compared with MMS alone (OR, 3.3; 95% CI, 1.8-5.9). Pooled data from comparative and noncomparative studies showed a local recurrence rate of 7% after WLE (95% CI, 5%-11%), 3% after staged excision (95% CI, 2%-4%), and less than 1% after MMS (95% CI, 0%-1%). Statistical heterogeneity was moderate to high.

CONCLUSION

Local recurrence of melanoma is significantly lower after MMS (<1%) and staged excision (3%) compared with WLE (7%).

Three-dimensional label-free histological imaging of whole organs by microtomy-assisted autofluorescence tomography

Three-dimensional (3D) histology is vitally important to characterize disease-induced tissue heterogeneity at the individual cell level. However, it remains challenging for both high-throughput 3D imaging and volumetric reconstruction. Here we propose a label-free, cost-effective, and ready-to-use 3D histological imaging technique, termed microtomy-assisted autofluorescence tomography with ultraviolet excitation (MATE). With the combination of block-face imaging and serial microtome sectioning, MATE can achieve rapid and label-free imaging of paraffin-embedded whole organs at an acquisition speed of 1 cm3 per 4 h with a voxel resolution of 1.2 × 1.2 × 10 μm3. We demonstrate that MATE enables simultaneous visualization of cell nuclei, fiber tracts, and blood vessels in mouse/human brains without tissue staining or clearing. Moreover, diagnostic features, including nuclear size and packing density, can be quantitatively extracted with high accuracy. MATE is augmented to the current slide-based 2D histology, holding great promise to facilitate histopathological interpretation at the organelle level.

Local Recurrence Rates of Skin Tumors After Resection With Complete Circumferential Peripheral and Deep Margin Assessment-Identification of High-Risk Entities

BACKGROUND

The local recurrence rates of malignant skin tumors after micrographic controlled surgery using complete circumferential peripheral and deep margin assessment (CCPDMA) are reported to be low. However, in daily practice, tumor entities with a significantly higher recurrence rate are found.

OBJECTIVE

The aim of the investigation was to identify these high-risk tumors to develop approaches for risk stratification.

PATIENTS AND METHODS

We included different malignant tumors that were surgically treated and examined with CCPDMA using paraffin sections and H&E staining. Re-excisions were performed until the tumor was completely removed.

RESULTS

Ninety-nine thousand three hundred seventy-two tumors were included in the study; the follow-up period was 4 years (median). Eight tumor entities were identified as high-risk entities, showing a significantly higher local recurrence rate of over 20%: desmoplastic squamous cell carcinoma, desmoplastic melanoma, Merkel cell carcinoma, microcystic adnexal carcinoma, pleomorphic sarcoma, liposarcoma as well as angiosarcoma, and extramammary Paget's disease.

CONCLUSION

Complete circumferential peripheral and deep margin assessment allows complete control of the resection margins and enables skin-sparing resections with low recurrence rates for basal cell carcinomas, nondesmoplastic squamous cell carcinomas, lentiginous melanomas, and dermatofibrosarcoma protuberans. However, other tumors show significantly higher recurrence rates and therefore need to be classified as high-risk tumors.

Invasive Melanoma and Melanoma in Situ Treated With Modified Mohs Micrographic Surgery With En Face Permanent Sectioning: A 10-Year Retrospective Review

BACKGROUND

Successful surgical treatment of cutaneous melanoma is dependent on margin control.

OBJECTIVE

To determine efficacy of modified Mohs micrographic surgery (mMMS) with en face permanent margins in management of invasive melanoma (IM) and melanoma in situ (MIS).

METHODS

A retrospective cohort study evaluating local recurrence, 5-year recurrence-free survival, and 5-year melanoma-specific survival. Overall, 657 melanomas (128 IM and 529 MIS) from 631 patients were treated using mMMS during a 10-year period. Follow-up information was obtained from medical records and telephone encounters.

RESULTS

The median follow-up time was 5.18 years. Most melanomas were located on the head and neck 93.6% (615/657). Margins required for clearance were 0.77 ± 0.44 cm (mean ± SD). Local recurrence was identified in 1.98% (13/657) of melanomas with no local recurrences in IM. Five-year local recurrence-free and melanoma-specific survival rates were estimated to be 96.9% (95% confidence interval [CI]: 94.6%-98.2%) and 99.0% (95% CI: 97.7%-99.6%). There were 5 melanoma-related deaths.

CONCLUSION

Modified Mohs micrographic surgery is an effective treatment of melanoma as evidenced by low local recurrence rates and high melanoma-specific survival.

European consensus-based interdisciplinary guideline for melanoma. Part 2: Treatment - Update 2019

A unique collaboration of multidisciplinary experts from the European Dermatology Forum, the European Association of Dermato-Oncology and the European Organization for Research and Treatment of Cancer (EORTC) was formed to make recommendations on cutaneous melanoma diagnosis and treatment, based on systematic literature reviews and the experts' experience. Cutaneous melanomas are excised with 1- to 2-cm safety margins. Sentinel lymph node dissection shall be performed as a staging procedure in patients with tumour thickness ≥1.0 mm or ≥0.8 mm with additional histological risk factors, although there is as yet no clear survival benefit for this approach. Therapeutic decisions in stage III/IV patients should be primarily made by an interdisciplinary oncology team ("Tumor Board"). Adjuvant therapies in stage III/IV patients are primarily anti-PD-1, independent of mutational status, or dabrafenib plus trametinib for BRAF-mutant patients. In distant metastasis, either resected or not, systemic treatment is indicated. For first-line treatment, particularly in BRAF wild-type patients, immunotherapy with PD-1 antibodies alone or in combination with CTLA-4 antibodies shall be considered. In particular scenarios for patients with stage IV melanoma and a BRAF-V600 E/K mutation, first-line therapy with BRAF/MEK inhibitors can be offered as an alternative to immunotherapy. In patients with primary resistance to immunotherapy and harbouring a BRAF-V600 E/K mutation, this therapy shall be offered in second-line. Systemic therapy in stage III/IV melanoma is a rapidly changing landscape, and it is likely that these recommendations may change in the near future.

Mohs surgery for the treatment of lentigo maligna and lentigo maligna melanoma - a systematic review

BACKGROUND

The role of Mohs micrographic surgery (MMS) in the treatment of lentigo maligna (LM), and lentigo maligna melanoma (LMM) has been controversial. The use of frozen sections is commonly cited as a suboptimal way to distinguish atypical melanocytes, resulting in traditional wide-local excision techniques as the mainstay of therapy.

OBJECTIVE

To compare the success of MMS as a treatment option for LM and LMM with that of traditional surgical and nonsurgical therapies by analyzing the published recurrence rates of these lesions after MMS procedures.

METHODS AND MATERIALS

PubMed database was used to find relevant articles with search terms related to MMS, LM, and LMM.

RESULTS

The search strategy resulted in 27 articles that fulfilled the inclusion criteria. All studies considered; MMS provided a 1.35% recurrence rate with follow-up times ranging from 1 month to 5 years. Specifically, studies employing classical MMS and MMS with rush sections provided recurrence rates of 1.17% and 2.4%, respectively.

CONCLUSION

MMS is one of the most successful treatment options for LM and LMM, with published evidence of improved recurrence rates when compared to other forms of therapy. Additional clinical trials are needed to further delineate the role of MMS in the treatment algorithm for these conditions.

A Retrospective Cohort Study on Patients with Lentigo Maligna Melanoma

BACKGROUND

More epidemiological data about lentigo maligna melanoma (LMM) are required to define follow-up guidelines. The study focused on recurrence, progression, and overall survival of LMM managed with primary wide local excision.

METHODS

In a 23-year retrospective study (1994 to 2016), a cohort of patients with LMM was evaluated by collecting data about the tumor location, the Breslow depth, the presence of ulceration, and patients' age and sex. Local recurrences, locoregional and distant metastases, and disease-free and overall survival were additionally assessed.

RESULTS

Overall, 150 cases (84 male, 66 female, mean age 71.3 ± 11.3 years) of single, localized, primary LMM with a mean follow-up of 6.6 ± 4.4 years were included. A total of 33 (22.2%) patients underwent sentinel lymph node biopsy (SLNB) during surgical excision. However, positive SLNB was detected in none of them. The multivariable Cox analysis indicated that age of diagnosis and male gender significantly influenced the overall survival, while a shorter disease-free survival could be correlated with a greater Breslow thickness. The metastatic potential turned out to be low, entailing 7 deaths in the context of the LMM.

CONCLUSION

Male gender, age over 70 at diagnosis, and a Breslow thickness greater than 0.75 mm were associated with a statistically significant decrease in overall disease-free survival in the current study. The results of the study confirm the favorable outcome of LMM. However, diagnosed patients should undertake regular follow-ups. The intensity of follow-up in these patients can be individualized based on the probability of recurrence/metastasis and overall survival. Furthermore, the study showed that SLNB might not be a necessary staging procedure in patients with LMM.

Diagnostic accuracy of a new ex vivo confocal laser scanning microscope compared to H&E-stained paraffin slides for micrographic surgery of basal cell carcinoma

BACKGROUND

For safe excision of malignant skin tumours, complete negative surgical margins are mandatory. The gold standard for analysis is frozen sections or paraffin-embedded haematoxylin and eosin (H&E)-stained slides. The production of H&E-stained slides is time-consuming (>20 h) while wounds remain unclosed. An upcoming method is confocal laser scanning microscopy (CLSM), a technique that scans unfixed fresh tissue rapidly.

OBJECTIVE

Evaluation of the process to generate and analyse CLSM images and assessment of the accuracy to detect basal cell carcinoma (BCC) tissue.

METHODS

Digital microscopic images were generated by the Histolog Scanner v1 from 544 fresh specimens of 148 BCCs that had been stained with a 0.01% proflavine solution. CLSM images were compared to the histological diagnoses of the corresponding H&E-stained slides.

RESULTS

A total of 525 images could be analysed. The sensitivity was 73% (95% CI = [65.27%; 80.47%]), and the specificity was 96% (95% CI = [93.40%; 97.60%]). Detection of BCCs in punch biopsies was certainly detected (sensitivity of 100%). The median total time to generate and evaluate a CLSM image was 5.17 min (maximum 20.17 min and minimum 2.05 min). The greatest challenge was flattening the specimen to assure complete representation of the surgical margins.

CONCLUSION

Confocal laser scanning microscopy is a time-saving and very effective alternative to classical paraffin-embedded or frozen sections. Patient treatment could be improved due to shorter hospital stays or faster outpatient therapy due to reduced intervals between surgical stages. Diagnostic accuracy of the microscope used still must be improved.

S1 guideline: microscopically controlled surgery (MCS)

When using procedures that enable complete examination of surgical margins (3D histology), microscopically controlled surgery (MCS) represents a safe and proven method to confirm R0 resection of infiltrating tumors, especially at problematic sites, while preserving the adjacent tissue. This allows for excellent or good aesthetic results that are superior (cryosurgery, short-range irradiation) or equivalent (PDT) to nonsurgical and less safe procedures (PDT).

Diagnosis and treatment of melanoma. European consensus-based interdisciplinary guideline - Update 2016

Cutaneous melanoma (CM) is potentially the most dangerous form of skin tumour and causes 90% of skin cancer mortality. A unique collaboration of multi-disciplinary experts from the European Dermatology Forum, the European Association of Dermato-Oncology and the European Organisation of Research and Treatment of Cancer was formed to make recommendations on CM diagnosis and treatment, based on systematic literature reviews and the experts' experience. Diagnosis is made clinically using dermoscopy and staging is based upon the AJCC system. CMs are excised with 1-2 cm safety margins. Sentinel lymph node dissection is routinely offered as a staging procedure in patients with tumours >1 mm in thickness, although there is as yet no clear survival benefit for this approach. Interferon-α treatment may be offered to patients with stage II and III melanoma as an adjuvant therapy, as this treatment increases at least the disease-free survival and less clear the overall survival (OS) time. The treatment is however associated with significant toxicity. In distant metastasis, all options of surgical therapy have to be considered thoroughly. In the absence of surgical options, systemic treatment is indicated. For first-line treatment particularly in BRAF wild-type patients, immunotherapy with PD-1 antibodies alone or in combination with CTLA-4 antibodies should be considered. BRAF inhibitors like dabrafenib and vemurafenib in combination with the MEK inhibitors trametinib and cobimetinib for BRAF mutated patients should be offered as first or second line treatment. Therapeutic decisions in stage IV patients should be primarily made by an interdisciplinary oncology team ('Tumour Board').

A Retrospective Review of Reconstructive Options and Outcomes of 202 Cases Large Facial Mohs Micrographic Surgical Defects, Based on the Aesthetic Unit Involved

BACKGROUND

For optimal treatment of facial defects following Mohs micrographic surgery (MMS), the aesthetic unit principles should be applied. Often multiple staged procedures and revisions are necessary.

OBJECTIVE

To analyze the reconstructive options and outcomes for complex facial defects per aesthetic unit.

METHODS

Data of 202 patients, who underwent a facial reconstruction at the department of plastic and reconstructive surgery following MMS, were collected.

RESULTS

The central facial units were affected in more than 70%, with over 20% of the defects involving more than 1 unit. Nasal defects required the longest reconstruction time (3-staged forehead flap) and periocular defects the most revisional procedures. In more than 50%, additional operations (range, 1-5) were needed. In 12%, postoperative complications occurred.

CONCLUSION

An overview for the reconstructive options of extensive facial skin cancer is presented. Proper treatment requires a structured multidisciplinary approach in order to achieve excellent tumour control and a satisfactory aesthetic and functional end result.

[Local recurrence and survival in acral lentiginous melanoma comparing 3D histology and conventional histology]

BACKGROUND

Surgical treatment of acral lentiginous melanomas with wide excisional margins as recommended often requires amputation of distal extremities. The current study analyzes, if smaller excisions in combination with a complete histological evaluation of the excisional margins (3D histology) have a negative impact on the prognosis.

PATIENTS AND METHODS

304 patients were retrospectively evaluated. 192 patients with reduced excisional margins followed by 3D histology (group A) were compared with 112 patients treated with conventional wide margins (group B). The outcome of both groups was compared.

RESULTS

The median tumor thickness was higher in group A (p = 0.022) and ulcerations occured more frequently (p = 0.017). The median excisional margin was 8 mm in group A and 20 mm in group B (p < 0.0001). 10.9 % (4.2 % invasive) of group A und 8.9 % (4.5 %invasive) of group B (p = 0.577) developed a local recurrence in a median of 40 months.The melanoma specific 10-year survival was 66.8 % in group A und 63.4 % in group B(p = 0.531). Survival of patients with or without local recurrence showed no difference(p = 0.643).

CONCLUSIONS

Excision with small margins followed by 3D histology is not inferior to conventional surgery with wide margins concerning the rate of local recurrences and has no negative impact on prognosis or the further course of the disease. Local recurrences are rare and do not influence the survival.

In vivo reflectance confocal microscopy to optimize the spaghetti technique for defining surgical margins of lentigo maligna

BACKGROUND

Lentigo maligna (LM) is a therapeutic challenge for surgeons because of its location in aesthetic areas and the difficulty in determining margins.

OBJECTIVE

To investigate a new procedure combining the "spaghetti" technique described by Gaudy-Marqueste and colleagues in 2011 with in vivo reflectance confocal microscopy (RCM) to define the margins of LM more accurately and allow strict histologic control.

METHODS AND MATERIALS

Thirty-three consecutive patients with LM of the head underwent a RCM-guided delineation of the margins followed by the "spaghetti" technique.

RESULTS

The excision of the first "spaghetti" in a tumor-free area was obtained in 28 of 33 patients. In the other five cases, persistence of LM foci was found in <5% of the length of spaghetti. The average number of pieces of "spaghetti" was 1.2 (range 1-3). Definitive histologic examination of the lesion showed a minimum average margin of 2.7 mm. Follow-up in 27 patients after an average of 10 months (range 4-25 months) did not show any recurrence.

CONCLUSION

This procedure allows accurate definition of the surgical margins of LM, with a low rate of multiple excisions, sparing tissue in functional and aesthetic areas. These results should be confirmed on the basis of a larger series with longer follow-up.

Diagnosis and treatment of melanoma. European consensus-based interdisciplinary guideline--Update 2012

Cutaneous melanoma (CM) is potentially the most dangerous form of skin tumour and causes 90% of skin cancer mortality. A unique collaboration of multi-disciplinary experts from the European Dermatology Forum (EDF), the European Association of Dermato-Oncology (EADO) and the European Organization of Research and Treatment of Cancer (EORTC) was formed to make recommendations on CM diagnosis and treatment, based on systematic literature reviews and the experts' experience. Diagnosis is made clinically and staging is based upon the AJCC system. CMs are excised with one to two centimetre safety margins. Sentinel lymph node dissection (SLND) is routinely offered as a staging procedure in patients with tumours more than 1mm in thickness, although there is as yet no clear survival benefit for this approach. Interferon-α treatment may be offered to patients with stage II and III melanoma as an adjuvant therapy, as this treatment increases at least the disease-free survival (DFS) and less clear the overall survival (OS) time. The treatment is however associated with significant toxicity. In distant metastasis, all options of surgical therapy have to be considered thoroughly. In the absence of surgical options, systemic treatment is indicated. BRAF inhibitors like vemurafenib for BRAF mutated patients as well as the CTLA-4 antibody ipilimumab offer new therapeutic opportunities apart from conventional chemotherapy. Therapeutic decisions in stage IV patients should be primarily made by an interdisciplinary oncology team ('tumour board').

Micrographic surgery of skin cancer in German hospitals 2005-2006

BACKGROUND/OBJECTIVE

Surgical therapy of skin cancer includes conventional wide excision and micrographic surgery (MS). Little is known about the population-wide spread of MS for the treatment of skin cancer. The aim was to estimate the in-hospital use of MS for the treatment of skin cancer in Germany.

METHODS

We used nationwide DRG data from 2005 through 2006. We identified hospitalizations with a main diagnosis of cutaneous malignant melanoma (CMM) (ICD-10: C43) or non-melanoma skin cancer (NMSC) (ICD-10: C44). MS was identified by OPS procedure codes including 5-895.1, 5-895.3, 5-212.1, 5-181.1, 5-181.4, 5-181.6, 5-182.1, 5-091.1, or 5-091.3.

RESULTS

We identified 52 660 and 98 484 hospitalizations with a primary diagnosis of CMM and NMSC respectively; 54.6% and 36.5% of NMSC and CMM-related admissions with local skin cancer treatment included MS. The relative frequency of MS varied by anatomic subsite of the skin cancer and by region of the hospital. Local infections were the most frequent complications after MS with 3.2-4.0% for NMSC and 2.3-2.9% for CMM followed by haemorrhages. Dehiscence of the operation wound is a rare event with risks ranging between 0.1% and 0.3%.

CONCLUSIONS

Micrographic surgery is frequently used for the local treatment of NMSC and varies considerably across Federal States of Germany. It is difficult to speculate how many MS might be performed in private or ambulatory settings in Germany. As MS requires surgical expertise, technical support and dermatopathology, we speculate that MS is much less frequently undertaken in private practices in Germany.

Jet fuel toxicity: skin damage measured by 900-MHz MRI skin microscopy and visualization by 3D MR image processing

The toxicity of jet fuels was measured using noninvasive magnetic resonance microimaging (MRM) at 900-MHz magnetic field. The hypothesis was that MRM can visualize and measure the epidermis exfoliation and hair follicle size of rat skin tissue due to toxic skin irritation after skin exposure to jet fuels. High-resolution 900-MHz MRM was used to measure the change in size of hair follicle, epidermis thickening and dermis in the skin after jet fuel exposure. A number of imaging techniques utilized included magnetization transfer contrast (MTC), spin-lattice relaxation constant (T1-weighting), combination of T2-weighting with magnetic field inhomogeneity (T2*-weighting), magnetization transfer weighting, diffusion tensor weighting and chemical shift weighting. These techniques were used to obtain 2D slices and 3D multislice-multiecho images with high-contrast resolution and high magnetic resonance signal with better skin details. The segmented color-coded feature spaces after image processing of the epidermis and hair follicle structures were used to compare the toxic exposure to tetradecane, dodecane, hexadecane and JP-8 jet fuels. Jet fuel exposure caused skin damage (erythema) at high temperature in addition to chemical intoxication. Erythema scores of the skin were distinct for jet fuels. The multicontrast enhancement at optimized TE and TR parameters generated high MRM signal of different skin structures. The multiple contrast approach made visible details of skin structures by combining specific information achieved from each of the microimaging techniques. At short echo time, MRM images and digitized histological sections confirmed exfoliated epidermis, dermis thickening and hair follicle atrophy after exposure to jet fuels. MRM data showed correlation with the histopathology data for epidermis thickness (R(2)=0.9052, P<.0002) and hair root area (R(2)=0.88, P<.0002). The toxicity of jet fuels on skin structures was in the order of tetradecane>hexadecane>dodecane. The method showed a sensitivity of 87.5% and a specificity of 75%. By MR image processing, different color-coded skin structures were extracted and 3D shapes of the epidermis and hair follicle size were compared. In conclusion, high-resolution MRM measured the change in skin epidermis and hair follicle size due to toxicity of jet fuels. MRM offers a three-dimensional spatial visualization of the change in skin structures as a method of toxicity evaluation and for comparison of jet fuels.

The impact of in vivo reflectance confocal microscopy on the diagnostic accuracy of lentigo maligna and equivocal pigmented and nonpigmented macules of the face

Limited studies have reported the in vivo reflectance confocal microscopy (RCM) features of lentigo maligna (LM). A total of 64 RCM features were scored retrospectively and blinded to diagnosis in a consecutive series of RCM sampled, clinically equivocal, macules of the face (n=81 LM, n=203 benign macules (BMs)). In addition to describing RCM diagnostic features for LM (univariate), an algorithm was developed (LM score) to distinguish LM from BM. This comprised two major features each scoring +2 points (nonedged papillae and round large pagetoid cells > 20 microm), and four minor features; three scored +1 point each (three or more atypical cells at the dermoepidermal junction in five 0.5 x 0.5 mm(2) fields, follicular localization of atypical cells, and nucleated cells within the dermal papillae), and one (negative) feature scored -1 point (a broadened honeycomb pattern). A LM score of > or = 2 resulted in a sensitivity of 85% and specificity of 76% for the diagnosis of LM (odds ratio (OR) for LM 18.6; 95% confidence interval: 9.3-37.1). The algorithm was equally effective in the diagnosis of amelanotic lesions and showed good interobserver reproducibility (87%). In a test set of 29 LMs and 44 BMs, the OR for LM was 60.7 (confidence interval: 11.9-309) (93% sensitivity, 82% specificity).

Melanoma Margin Assessment

Primary cutaneous melanoma is treated by excisional surgery and careful histologic assessment of the specimen margins is a crucial component of pathology reporting. Surgical margins may be assessed by conventional transverse (bread-loaf) vertical sections, by en face vertical sections, or by en face oblique sections. Transverse techniques only sample a small percentage of the surgical margin. En face techniques are technically challenging but allow assessment of close to 100% of the margin. Margin assessment for melanoma removed from chronically sun-damage skin is difficult. Melanoma in situ shows contiguous melanocyte growth, nesting, or intraepidermal pagetoid spread. Pitfalls include solar melanocytic hyperplasia, solar lentigines, melanocytic hyperplasia secondary to previous biopsy, lichenoid reactions, and invasive melanoma mimicking scar or benign nevus. En face sections can be used to assess margins for melanoma on sun-damaged skin, and evidence suggests that frozen sections may also be employed by experienced clinicians. Immunohistochemistry is a useful ancillary technique, enabling more accurate identification of in situ melanoma within a surgical margin.

Analysis of risk factors determining prognosis of cutaneous squamous-cell carcinoma: a prospective study

BACKGROUND

Cutaneous squamous-cell carcinomas (SCC) are among the most common cancers capable of metastasis. Current Tumour Node Metastasis (TNM) staging includes horizontal tumour size, involvement of extradermal structures, and degree of differentiation. The aim of this study was to prospectively analyse the key factors predicting metastasis and local recurrence in cutaneous SCC.

METHODS

We assessed prospectively investigated potential risk factors for metastasis or local recurrence of SCC, previously suggested by retrospective studies and small case series, in 615 white patients. Between Jan 1, 1990, and Dec 31, 2001, all patients underwent surgery for cutaneous SCC with complete histological examination of the three-dimensional excision margins (3D-histology) in one centre. Univariate and multivariate analysis included tumour thickness, horizontal size, body site, histological differentiation, desmoplastic growth, history of multiple SCC, and immunosuppression. Primary endpoints were time to metastasis and time to local recurrence, defined as the time from date of diagnosis of the primary tumour to the date of diagnosis of metastasis or local recurrence, respectively.

FINDINGS

653 patients were enrolled in the study. 38 patients were lost to follow-up leaving 615 assessable patients (median age 73 years [range 27-98]). During a median follow-up period of 43 months (range 1-165), 26 (4%) of 615 patients developed metastases and 20 patients developed local recurrence (3%). Tumours 2.0 mm or less in thickness did not metastasise. Metastases occurred in 12 (4%) of 318 tumours between 2.1 mm and 6.0 mm in thickness, and in 14 (16%) of 90 tumours with a thickness greater than 6.0 mm. On multivariate analysis, key prognostic factors for metastasis were increased tumour thickness (hazard ratio 4.79 [95% CI 2.22-10.36]; p<0.0001), immunosuppression (4.32 [1.62-11.52]; p=0.0035), localisation at the ear (3.61 [1.51-8.67]; p=0.0040), and increased horizontal size (2.22 [1.18-4.15]; p=0.0128). The risk of local recurrence depended on increased tumour thickness (6.03 [2.71-13.43]; p<0.0001) and desmoplasia (16.11 [6.57-39.49]; p<0.0001).

INTERPRETATION

Only SCC greater than 2.0 mm in thickness are associated with a significant risk of metastasis. Tumours greater than 6.0 mm are associated with a high risk of metastasis and local recurrence. Desmoplastic growth is an independent risk factor for local recurrence. Studies should assess the role of follow-up visits and sentinel-lymph-node biopsy in high-risk patients.

3D-Histological evaluation of surgery in dermatofibrosarcoma protuberans and malignant fibrous histiocytoma: Differences in growth patterns and outcome

AIMS

To evaluate the microscopic growth pattern of dermatofibrosarcoma protuberans (DFSP) and malignant fibrous histiocytoma (MFH) and the long-term outcome using 3D-histologic surgery with paraffin sections to cover complete margins and to detect subclinical spreads very sensitively.

METHODS

One hundred and one patients have been included comprising 70 DFSP, 31 MFH. Data from 87 patients treated since 1992 were collected prospectively.

RESULTS

Mean clinical tumor-size was 45 mm, mean histological tumor size 65 mm. A mean excision margin of 19 mm achieved negative margins. The histological infiltration shows an asymmetrical pattern with horizontal or vertical extension either cord-, sector- or multiple-like up to 70 mm in length, detectable by 3D-histology. Age and localization differed significantly between DFSP and MFH lesions. MFH tumors had a significantly deeper infiltration than DFSP. The mean follow up was 60 months. In 70 patients with DFSP one local recurrence after 62 months occurred, but no metastasis. 31 patients with MFH developed 8 local recurrences, and 4 metastases (lymph nodes and/ or lungs); 3 of them died of the disease, all 3 had a postoperative status of R1 (p=0.001).

CONCLUSIONS

There are significant differences in growth pattern and clinical outcome between DFSP and MFH. DFSP can be cured by surgery following 3D-histology with paraffin sections. MFH is significantly more malignant. After local R0-resection proofed by 3D-histology higher cure rates can be achieved.

Cryosurgical treatment of lentigo maligna

BACKGROUND

Lentigo maligna (LM) is a common melanocytic malignancy which requires therapy because of the risk of progression to invasive lentigo maligna melanoma which a much worse prognosis.

PATIENTS AND METHODS

18 patients with clinical and histopathological diagnosis of LM were treated with cryosurgery. The patients were older Caucasians (mean age 59.5 years) and 11 were male. They were chosen for cryosurgery because the lesion posed a surgical challenge or the patient was not a good surgical candidate. They were treated with two freeze-thaw cycles of liquid nitrogen under local anesthesia in a single sitting. Lesions larger than 2 cm(2) were divided into smaller segments for freezing.

RESULTS

The lesions resolved clinically in all cases, with no recurrence or metastasis detected during a mean follow-up of 75.5 months. Some patients developed hypopigmented scars.

CONCLUSIONS

Cryosurgery with liquid nitrogen is an efficient, safe and in most cases aesthetically acceptable alternative method to treat LM.

Histologie 3D : une technique de chirurgie micrographique adaptée aux dermatologues et pathologistes hospitaliers et libéraux

We present 2 techniques of micrographic surgery (3D-histology) useful to control lateral and deep limits of cutaneous tumors. We have adapted the protocol created in Germany, at the University of Tuebingen, for French pathologists and dermatologists.

A confusing world: what to call histology of three-dimensional tumour margins?

Complete three-dimensional histology of excised skin tumour margins has a long tradition and, unfortunately, a multitude of names as well. Mohs, who introduced it, called it 'microscopically controlled surgery'. Others have described it as 'micrographic surgery', 'Mohs' micrographic surgery', or simply 'Mohs' surgery'. Semantic confusion became truly rampant when variant forms, each useful in its own way for detecting subclinical outgrowths of malignant skin tumours, were later introduced under such names as histographic surgery, systematic histologic control of the tumour bed, histological control of excised tissue margins, the square procedure, the perimeter technique, etc. All of these methods are basically identical in concept. All involve complete, three-dimensional histological visualization and evaluation of excision margins. Their common goal is to detect unseen tumour outgrowths. For greater clarity, the authors of this paper recommend general adoption of '3D histology' as a collective designation for all the above methods. As an added advantage, 3D histology can also be used in other medical disciplines to confirm true R0 resection of, for example, breast cancer or intestinal cancer.