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.

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

BACKGROUND

Although current guidelines recommend a 5 mm surgical margin for the excision of melanoma in situ (MIS), increasing evidence has shown this may be suboptimal to achieve tumor clearance.

OBJECTIVE

To evaluate margins required for optimal cure rates with excision of MIS on the head and neck and investigate tumor and/or patient factors in those requiring >5 mm margins to achieve tumor clearance.

METHODS

A retrospective chart review was performed on 846 (807 primary and 39 recurrent) MIS cases on the head and neck treated in the authors' dermatologic surgery department over a 126-month (10.5 year) period.

RESULTS

Sixty-two percent were cleared with 5 mm margins. A total of 15 mm margins were required to achieve a 97% clearance rate. Difference in clearance rate between margin thresholds was significant (P < .001). Tumor location on the cheek and larger preoperative size correlated with requiring >5 mm margins to achieve tumor clearance (P = .006 and P = .001, respectively).

LIMITATIONS

This is a single-center retrospective study which relies on accurate documentation of clinical data.

CONCLUSION

This study demonstrates that MIS on the head and neck often requires margins >5 mm margins to achieve tumor clearance. When Mohs micrographic surgery is not possible, excision margins of ≥10 mm are likely necessary for head and neck tumors.

Topical and Intralesional Immunotherapy for Melanoma In Situ: A Review

The incidence of in situ melanoma (MIS) has increased over the last decades. The mainstay of treatment for MIS, including lentigo maligna (LM), is complete surgical excision with clear margins (0.5 to 1.0 cm). Nevertheless, MIS lesions often affect elderly patients with comorbidities and involve large lesions in cosmetically sensitive areas, which means surgery is not always appropriate. Non-surgical treatments have a role in these cases, and include radiotherapy, cryosurgery, immunotherapy, laser therapy, and other topical medications. This study aims to review the applications of immunotherapy in MIS, either in monotherapy or in combination with other therapeutic alternatives. The main forms of immunotherapy used are imiquimod and, to a lesser extent, intralesional interferon-α (IL-INF-α) and ingenol mebutate (IM). IL-INF-α and IM have not been studied as extensively as imiquimod, whose results in real-life practice are encouraging. The clearance and recurrence rates reported in MIS treated with imiquimod as monotherapy, or as an adjuvant after surgery with affected or narrow margins, make imiquimod a reliable therapeutic alternative in selected cases. Also, its use as a neoadjuvant therapy before surgery was shown to reduce the final surgical defect size required to confirm negative histologic margins. In conclusion, local immunotherapy is frequently used in clinical practice and experience confirms it to be an excellent option for certain patients.

Double V-Y Island Pedicle Flap for Dorsal Hand Reconstruction Following Mohs Micrographic Surgery

Medium to large defects on the dorsal hand pose a reconstructive challenge following dermatologic surgery. Repairs in this location can be complicated by a paucity of adjacent tissue reservoirs, competing tension vectors, thin cutaneous tissue, and superficial tendons and vasculature. In such cases, a double V-Y island pedicle flap is an effective reconstructive solution. It preserves hand function, harnesses local tissue with a robust blood supply, facilitates complete closure, and provides skin that closely matches the original's color and texture. Here, we present the repair of a medium to large dorsal hand defect after Mohs micrographic surgery for melanoma in situ, using a double V-Y island pedicle flap.

Spiny Keratoderma in Association with Melanoma

Spiny keratoderma (SK) was first described by Brown in 1871 and is characterized by numerous 1-2 mm spines of keratin on the palms and soles, usually sparing the dorsal surfaces, or disseminated over the trunk. Histologically, the "spine" represents a column of hyperkeratosis. Several different forms are known, including familial, sporadic, post-inflammatory and paraneoplastic. Although an association of SK with melanoma has been reported, the significance of such co-occurrence remains unclear due to the limited number of cases. To increase the body of knowledge and shed further light on this rare condition, we present a case of SK in a patient with a recent history of melanoma in situ.

Is It Time to Supersede the Diagnostic Term "Melanoma In Situ with Regression?" A Narrative Review

Traditionally, the term melanoma in situ (MIS) is used to designate a horizontal (radial) growth phase of malignant melanoma (MM) in which there is no histological evidence of any invasion (or microinvasion) of neoplastic melanocytic cells into the superficial or papillary dermis. In daily dermatopathological practice, we are faced with misleading definitions, such as "melanoma in situ with regression," which risk affecting homogeneity for comparison purposes of pathological reports of malignant melanoma. The authors conducted a literature review using PubMed and Web of Science (WoS) as the main databases and using the following keywords: "Malignant Melanoma in situ" or "Melanoma in situ" and "regression" and/or "radial growth phase regression." A total of 213 articles from both analyzed databases were retrieved; finally, only eight articles in English were considered suitable for the chosen inclusion criteria. In consideration of the absence of studies with large case series, of reviews with meta-analyses, and, therefore, of a broad scientific consensus, expressions including "melanoma in situ with regression" should be avoided in the histopathological report. Instead, they should be replaced with clearer and more exhaustive definitions.

Melanoma In Situ of the Hard Palate

Mucosal melanoma of the oral cavity is rare and highly aggressive, thought to represent less than 1% of melanomas. Within this subgroup, melanoma in situ has been rarely described. We describe the case of a 54-year-old male with history of tobacco use presented with extensive pigmented changes to the hard and soft palate. Biopsy demonstrated melanoma in situ. Mucosal surgical resection was performed with all peripheral epithelial margins involved and negative deep margins. After extensive multidisciplinary discussion, remaining mucosal margins were re-resected to the teeth and posteriorly onto the soft palate. Deep margins remained negative with melanoma in situ still present peripherally. The patient is routinely surveilled without evidence of recurrence. Oral cavity melanoma in situ has been rarely described. The treatment of choice is surgical excision, ranging from wide local excision to composite resections, with consideration given to medical adjuncts. This unique entity should be considered in pigmented oral abnormalities.

Use of PRAME immunostaining to distinguish early melanoma in situ from benign pigmented conditions

BACKGROUND

PRAME (PReferentially expressed Antigen in MElanoma) is an antigen that shows marked overexpression in melanoma compared to normal skin melanocytes. PRAME immunohistochemistry has proven effective in distinguishing melanocytic nevi from melanoma, but it is unclear if it may be used to distinguish melanoma in situ from other benign pigmented lesions. In particular, differentiating from melanocytic hyperplasia in sun-damaged skin is sometimes clinically and histopathologically challenging. We hypothesized that PRAME staining of solar lentigo, sun-damaged skin, and melanoma in situ would aid in setting a threshold of positivity that could be useful in evaluating such conditions.

METHODS

We collected and stained typical examples of solar lentigo, melanoma in situ, and non-lesional sun-damaged skin by PRAME immunohistochemistry to assess a potential cutoff of PRAME positivity.

RESULTS

Solar lentigo and non-lesional sun-damaged skin had 10 or fewer PRAME-positive cells per millimeter (mean 1.2), on the other hand melanoma in situ had at least 16 (mean 75.1).

CONCLUSIONS

PRAME immunostaining appears sensitive and specific in the current series. This could be clinically useful for distinguishing melanoma in situ from benign melanocytic hyperplasia in sun-damaged skin. However, further studies are required to determine if 10 cells per millimeter is an acceptable threshold of positivity.

Mammary Paget Disease With Melanocytic Proliferation Mimicking Malignant Melanoma in situ: A Case Report

Several cases of pigmented mammary Paget’s disease (PMPD) mimicking cutaneous malignant melanoma have been reported. In these cases, the tumor cells are colonized by melanocytes, particularly with the presence of a population of melanocytes staining for HMB-45 and S100. Here, we report a case of mammary Paget disease (MPD) which was misdiagnosed as melanoma in situ due to the interpretation of the staining of melanocytic markers S-100, Melan-A, and HMB-45. The tumor cells strongly expressed CK7 and GATA3, and a dual-labeling showed negative PHH3 labeling for the melanocytes. Pathologists need to be aware of the caveat of colonization of melanocytes in Paget disease.

Two-stage functional and aesthetic reconstructive surgery in melanoma in situ of the glans penis and urethra

Melanoma in situ including glans penis and fossa navicularis is unique and represents a challenging dilemma since surgery should not be very aggressive. We present a case of melanoma in situ treated with a two-stage penile and urethral reconstructive surgery, with emphasis on functional and aesthetic results. At the first-stage surgery an anatomic glansectomy was perfomed, and combined preputial and full-thickness skin grafts were used to prepare the urethral plate and restore the aesthetic aspect of the corpora cavernosa. After 6 months, the distal urethra was repaired including the configuration of an orthotopic meatus and a neo-glans.

PRAME immunohistochemistry as an adjunct for diagnosis and histological margin assessment in lentigo maligna

AIMS

Lentigo maligna (LM), the most common type of melanoma in situ, is a diagnostically challenging lesion for pathologists due to abundant background melanocytic hyperplasia in sun-damaged skin. Currently, no laboratory methods reliably distinguish benign from malignant melanocytes. However, preferentially expressed antigen in melanoma (PRAME) has shown promise in this regard, and could potentially be applied to diagnosis and margin assessment in difficult cases of LM.

METHODS AND RESULTS

Ninety-six cases with a diagnosis of LM (n = 77) or no residual LM (n = 19) following initial biopsy were identified and stained with an antibody directed towards PRAME. Immunohistochemistry (IHC) was scored as positive or negative, and measurement of histological margins by PRAME was performed and compared to the measurement of histological margins using conventional methods [haematoxylin and eosin (H&E) and/or sex-determining region Y-box 10 (SOX10) and/or Melan-A]. Of cases with LM, 93.5% (72 of 77) were PRAME+ and 94.7% (18 of 19) of cases with no residual LM were PRAME- . Of the 35 cases with no margin involvement by PRAME or conventional assessment, 14 cases (40.0%) had no difference in measurement, 17 (48.6%) had a difference of 1 mm or less and four (11.4%) differed by between 1 and 3.5 mm. There was a high correlation between margin assessment methods (r = 0.97, P < 0.0001).

CONCLUSIONS

PRAME IHC is a sensitive (93.5%) and specific (94.7%) method for diagnosing LM on biopsy and excision, and measurement of histological margins by PRAME shows a high correlation with conventional methods for margin assessment. Furthermore, the nuclear expression of PRAME makes it a good target for use in dual-colour IHC stains.

Change in lentigo maligna score assessed by in vivo reflectance confocal microscopy after 1 month of imiquimod treatment for lentigo maligna management

BACKGROUND

Treatment of lentigo maligna (LM) is challenging because of the potential functional and esthetic surgical sequelae. Imiquimod has been proposed as a treatment for LM. Reflectance confocal microscopy (RCM) is a noninvasive method for the diagnosis of LM and margin assessment.

OBJECTIVES

To compare the overall LM score (LMS) assessed by RCM before and 1 month after the start of imiquimod treatment compared to placebo and to define the immunohistochemical (IHC) profile of responders to imiquimod.

METHODS

A controlled randomized study was conducted. Forty patients underwent RCM examination with calculation of the LMS at baseline and after 1 month of treatment. An IHC analysis of excised tissues was performed.

RESULTS

The 1-month LMS was significantly lower in patients treated with imiquimod compared to those treated with placebo (P < .001). The criteria in the imiquimod-treated patients that demonstrated significant decrease were nonedged papillae; large, round pagetoid cells; atypical cells at the dermoepidermal junction; and follicular location of atypical cells. IHC analysis showed a higher level of interferon gamma in the resected specimens of patients responding to imiquimod (P = .04).

LIMITATIONS

Sample size was small.

CONCLUSION

Assessing the LMS by RCM was useful to monitor LM response to imiquimod accurately.

Epidemiology of Melanoma in the Czech Republic in East Bohemia in the Period 2002-2017 and the Effect of the Annual Sunshine Exposure

AIM

The evaluation of the trend in the occurrence of melanoma nodulare, melanoma superficiale, lentigo maligna and melanoma in situ in the period of 2002-2017 in East Bohemia region in the Czech Republic. We examine if the annual numbers of hours of sunshine could affect the number of patients with melanoma.

METHOD

In the peridod of 2002-2017, altogether 2230 patients with new diagnosis of melanoma were examined. We studied 1) If there is some trend in the occurrence of lentigo maligna and melanoma in situ, melanoma superficiale, and melanoma nodulare and if there is a difference in the age of patients with this diagnosis (adjusted calculation of specific kind of melanomas and adjusted calculation of age). 2) If the annual numbers of hours of sunshine affect the trend in the occurrence of melanoma and if the annual numbers of hours of sunshine affect the body site of melanoma.

RESULTS AND CONCLUSION

Our study confirmed that the number of patients with lentigo maligna and melanoma in situ had increased in East Bohemia region in the period of 2002-2017. The number of melanomas of nodular and superficial type does not increase. The total number of melanomas in this period does not increase either. No difference of the age of patients with melanoma nodulare, superficiale, lentigo maligna and melanoma in situ was confirmed. We confirmed no relation of the annual numbers of hours of sunshine to the number of melanoma and to the body site of melanoma.

Clinicopathological, immunohistochemical and fluorescence in-situ hybridisation features of early subungual melanoma: an analysis of 65 cases

AIMS

Very limited data are available concerning the clinicopathological and molecular features of early subungual melanoma (SM), especially with regard to the Asian population. The aim of this study was to investigate the clinical, histological, immunohistochemical and chromosomal features of early SM.

METHODS AND RESULTS

Fifty-two in-situ and 13 thin (Breslow thickness ≤1.0 mm) SM cases were retrospectively reviewed. All patients presented with longitudinal melanonychia involving a single digit, and the thumb was the most affected digit (35 of 65, 53.8%). Microscopically, most cases showed small to medium nuclear enlargement (58 of 65) and mild to moderate nuclear atypia (57 of 65). Hyperchromatism and irregular contours of nuclei were persistent features in all cases. The variation of melanocyte count (the number of melanocytes per mm dermal-epithelial junction) ranged from 31 to 255. Intra-epithelial mitoses were identified in 34 cases (52.3%). Statistically, features of in-situ lesions including higher melanocyte count (>70), presence of multinucleated melanocytes, inflammatory infiltrate and cutaneous adnexal extension, were associated with early invasion. Melan-A, human melanoma B (HMB)45, mouse monoclonal melanoma antibody (PNL2) and SOX10 antibodies (>95.0%) showed superior diagnostic sensitivity to S-100 protein (83.1%). Fluorescence in-situ hybridisation (FISH) results were positive in 15 of 23 successfully analysed cases.

CONCLUSIONS

To the best of our knowledge, this is the largest single-institution study of early SM in an Asian population, and the largest cohort tested by FISH. Early SM mainly showed small to medium nuclear enlargement and mild to moderate nuclear atypia. High melanocyte count, hyperchromatism and irregular contours of nuclei and intra-epithelial mitoses are crucial diagnostic parameters. Immunohistochemistry, especially SOX10 staining, and FISH analysis are valuable in the diagnosis of SM.

Morphological evolution in melanoma in situ using revised pattern analysis

Sequential digital dermoscopic imaging (SDDI) compares surface microscopy images of skin lesions over multiple time points. We utilized a retrospective SDDI cohort to investigate the development of dermoscopic features associated with malignancy in melanoma in situ (MIS). A total of 124 in situ melanomas were assessed from 110 Caucasian patients aged ≥18 years, with ≥2 serial images obtained between 1999 and 2017 and followed for a mean 41 months (3-142). As a positive control group, 58 invasive melanomas from 53 patients were also reviewed. Change in MIS size or number of colours correlated to time (both p < .001). The odds of MIS displaying ≥3 clues to malignancy also correlated to time (OR 5.6-52.1) (p < .05). 75% of in situ melanomas matched a dermoscopic subtype on final imaging. While a clinically significant minority of in situ melanomas were unchanged or lost dermoscopic features, lesions predominantly increased in morphological complexity over time. Longer follow-up periods allow dermoscopic features associated with malignancy and histopathological progression to develop.

Lentigo maligna melanoma in situ with neurotropism

Perineural invasion, or neurotropism, is defined by the presence of cancer cells either within the neuronal sheath or found along the nerves. In melanoma, it is most commonly associated with invasive desmoplastic melanoma, a melanoma that is most commonly associated with malignant melanoma in situ, lentigo maligna type. Initially, perineural invasion was included in the reported Breslow thickness; however, recent data suggest that it should not be included. In this report, we describe a case of malignant melanoma in situ, lentigo maligna type, with associated neurotropism in the absence of invasive component.

Superficial dermal melanocytosis of the elderly: An exceptional occurrence?

The development of flat pigmented lesions on chronically sun-damaged (CSD) skin of the face may represent the clinical manifestation of a wide variety of hyperplastic/neoplastic melanocytic proliferations. We report the exceptional case of an acquired pigmented patch occurring on CSD skin, histopathologically characterized by diffuse hyperplasia of dendritic/spindled melanocytes in the superficial dermis within a widened band of actinic elastosis. This lesion was associated with a small focus of early invasive lentigo maligna melanoma (LMM). We show the melanocytic nature of the population of dermal pigmented cells by means of single and double immunohistochemical staining for melanocytic and histiocytic markers. The biologic significance of the focus of LMM within the hyperpigmented lesion (whether random collision phenomenon or causally related occurrence), as well as the pathogenesis of the whole dermal lesion are difficult to elucidate. Our case emphasizes the need for a better understanding of the pathophysiology of so-called dermal melanocytes.

Association of Gender with Survival in Melanoma In Situ of the Head and Neck: A National Database Study

Introduction

While prior studies have addressed the gender-specific survival of malignant melanoma, such investigation is lacking for melanoma in situ (MIS) and for the sun-exposed head and neck areas. Understanding the role of patient characteristics on disease prognosis is essential in determining optimal patient treatment and follow-up. We conducted a retrospective cohort study of patients diagnosed with MIS of the head and neck to assess the association of gender with long-term survival.

Methods

First primary cases of MIS diagnosed between 1998 and 2015 were extracted from the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) database. Cox regression analysis adjusting for demographic, tumor, and treatment characteristics was used to evaluate all-cause and cancer-specific mortality risks.

Results

After adjusting for demographic, tumor, and treatment data, males demonstrated significantly poorer overall survival (hazard ratio [HR] 1.484; 95% confidence interval [CI] 1.332, 1.653; P<0.001) and cancer-specific survival (HR 1.571; 95% CI 1.056, 2.338; P=0.026) compared to their female counterparts.

Conclusion

Proposed reasons for these findings include gender-based hormonal influence on cancer growth and development, gender-specific health utilization behaviors, and gender-based cosmetic impact of cutaneous malignancies. These findings do have limitations, including its retrospective nature, possible upgrading of MIS diagnoses during the study period, miscoding, and inability to account of lifestyle/modifiable/environmental risk factors. Nevertheless, it suggests a gender-specific survival difference, which may be further investigated and considered as part of clinician awareness, influence patient counseling, and screening for such patients.

Meta-analysis of number needed to treat for diagnosis of melanoma by clinical setting

OBJECTIVE

To provide a formal statistical comparison of the efficacy of melanoma detection among different clinical settings.

METHODS

A systematic review and meta-analysis of all relevant observational studies on number needed to treat (NNT) in relation to melanoma was performed in MEDLINE. We performed a random-effects model meta-analysis and reported NNTs with 95% confidence intervals (CIs). The subgroup analysis was related to clinical setting.

RESULTS

In all, 29 articles including a total of 398,549 biopsies/excisions were analyzed. The overall NNT was 9.71 (95% CI, 7.72-12.29): 22.62 (95% CI, 12.95-40.10) for primary care, 9.60 (95% CI, 6.97-13.41) for dermatology, and 5.85 (95% CI, 4.24-8.27) for pigmented lesion specialists.

LIMITATIONS

There is heterogeneity in data reporting and the possibility of missing studies. In addition, the incidence of melanoma varies among clinical settings, which could affect NNT calculations.

CONCLUSION

Pigmented lesion specialists have the lowest NNT, followed by dermatologists, suggesting that involving specialists in the diagnosis and treatment of pigmented skin lesions can likely improve patient outcomes.

Pathologists' agreement on treatment suggestions for melanocytic skin lesions

BACKGROUND

Although treatment guidelines exist for melanoma in situ and invasive melanoma, guidelines for other melanocytic skin lesions do not exist.

OBJECTIVE

To examine pathologists' treatment suggestions for a broad spectrum of melanocytic skin lesions and compare them with existing guidelines.

METHODS

Pathologists (N = 187) completed a survey and then provided diagnoses and treatment suggestions for 240 melanocytic skin lesions. Physician characteristics associated with treatment suggestions were evaluated with multivariable modeling.

RESULTS

Treatment suggestions were concordant with National Comprehensive Cancer Network guidelines for the majority of cases interpreted as melanoma in situ (73%) and invasive melanoma (86%). Greater variability of treatment suggestions was seen for other lesion types without existing treatment guidelines. Characteristics associated with provision of treatment suggestions discordant with National Comprehensive Cancer Network guidelines were low caseloads (invasive melanoma), lack of fellowship training or board certification (melanoma in situ), and more than 10 years of experience (invasive melanoma and melanoma in situ).

LIMITATIONS

Pathologists could not perform immunohistochemical staining or other diagnostic tests; only 1 glass side was provided per biopsy case.

CONCLUSIONS

Pathologists' treatment suggestions vary significantly for melanocytic lesions, with lower variability for lesion types with national guidelines. Results suggest the need for standardization of treatment guidelines for all melanocytic lesion types.

Is melanocyte density our last hope? Comparison of histologic features of photodamaged skin and melanoma in situ after staged surgical excision with concurrent scouting biopsies

Differentiating melanocytic hyperplasia (MH) on photodamaged skin from junctional lentiginous melanocytic proliferations (JLMP), early evolving melanoma in situ (MIS), or the periphery of a lesion of MIS on staged excision can be challenging. Although previous cross-sectional studies have elucidated important criteria for distinguishing MH on photodamaged skin from more concerning lesions, this study highlights a technique to treat JLMP and MIS with staged mapped excision and baseline scouting biopsies of adjacent nonlesional photodamaged skin to assist in determination of surgical margin clearance. Additionally, we compare the lesional and photodamaged control biopsies from the same patient to evaluate relevant histologic criteria that may be used to distinguish MH in photodamaged skin from JLMP/MIS, while minimizing confounding factors. There was a statistically significant difference (P ≤ 0.05) found for melanocyte density, irregular melanocyte distribution, melanocyte clustering, follicular infundibulum involvement, and nesting. However, criteria such as nesting, epithelioid cells and melanocyte clustering were seen in both photodamaged skin and MIS. These findings underscore the fact that histologic features of photodamaged skin can overlap with the histopathological features of MIS. Of all of the criteria evaluated, melanocytic density was the most objective histologic criterion and did not show overlap between the sun-damaged and JLMP/MIS groups.

Primary excision margins, sentinel lymph node biopsy, and completion lymph node dissection in cutaneous melanoma: a clinical practice guideline

Background

For patients who are diagnosed with early-stage cutaneous melanoma, the principal therapy is wide surgical excision of the primary tumour and assessment of lymph nodes. The purpose of the present guideline was to update the 2010 Cancer Care Ontario guideline on wide local excision margins and sentinel lymph node biopsy (slnb), including treatment of the positive sentinel node, for melanomas of the trunk, extremities, and head and neck.

Methods

Using Ovid, the medline and embase electronic databases were systematically searched for systematic reviews and primary literature evaluating narrow compared with wide excision margins and the use of slnb for melanoma of the truck and extremities and of the head and neck. Search timelines ran from 2010 through week 25 of 2017.

Results

Four systematic reviews were chosen for inclusion in the evidence base. Where systematic reviews were available, the search of the primary literature was conducted starting from the end date of the search in the reviews. Where systematic reviews were absent, the search for primary literature ran from 2010 forward. Of 1213 primary studies identified, 8 met the inclusion criteria. Two randomized controlled trials were used to inform the recommendation on completion lymph node dissection.Key updated recommendations include:■ Wide local excision margins should be 2 cm for melanomas of the trunk, extremities, and head and neck that exceed 2 mm in depth.■ slnb should be offered to patients with melanomas of the trunk, extremities, and head and neck that exceed 0.8 mm in depth.■ Patients with sentinel node metastasis should be considered for nodal observation with ultrasonography rather than for completion lymph node dissection.

Conclusions

Recommendations for primary excision margins, sentinel lymph node biopsy, and completion lymph node dissection in patients with cutaneous melanoma have been updated based on the current literature.

Comparison of surgical margins for lentigo maligna versus melanoma in situ

BACKGROUND

Multiple studies have shown a 5-mm surgical margin to be inadequate for excision of melanoma in situ. Some have suggested that a wider margin is needed only for the lentigo maligna subtype.

OBJECTIVE

To compare subclinical extension of lentigo maligna with that of melanoma in situ. The secondary objective was to investigate the effect of other factors on extent of subclinical extension.

METHODS

A prospectively collected series of noninvasive melanomas was studied. Original pathology reports were used to identify lentigo maligna and compare data for that subtype with data for the remaining melanomas in situ.

RESULTS

A total of 1506 lentigo maligna cases and 829 melanomas in situ were included. To obtain a 97% clearance rate, both lentigo maligna and melanoma in situ required a 12-mm margin on the head and neck and a 9-mm margin on the trunk and extremities. Only 79% of lentigo maligna and 83% of melanoma in situ were successfully excised with a 6-mm margin (P = .12). Local recurrence was identified in 0.26% (5 facial, 1 scalp, and 1 acral), with a mean follow-up time of 5.7 years.

LIMITATIONS

Margins less than 6 mm were not studied. The use of lentigo maligna diagnosis was not used by all dermatopathologists consistently. The degree of surrounding photodamage was not assessed.

CONCLUSION

Subclinical extension of lentigo maligna and melanoma in situ are similar. Standard surgical excision of all melanoma in situ subtypes, including lentigo maligna, should include at least 9 mm of normal-appearing skin, which is similar to the amount recommended for early invasive melanoma. Lesions on the head and neck or those with a diameter greater than 1 cm may require even wider margins and are best treated with Mohs micrographic surgery. The perception that lentigo maligna has wider subclinical extension may be related to its frequent location on the head and neck, where photodamage can camouflage the clinical border.

Re-biopsy of partially sampled thin melanoma impacts sentinel lymph node sampling as well as surgical margins

AIM

To assess the impact of re-biopsy on partially sampled melanoma in situ (MIS), atypical melanocytic proliferation (AMP) and thin invasive melanoma.

MATERIALS & METHODS

We retrospectively identified cases of re-biopsied partially sampled neoplasms initially diagnosed as melanoma in situ, AMP or thin melanoma (Breslow depth ≤0.75 mm).

RESULTS & CONCLUSION

Re-biopsy led to sentinel lymph node biopsy (SLNB) in 18.3% of cases. No patients upstaged from AMP or MIS had a positive SLNB. One out of nine (11.1%) initially diagnosed as a thin melanoma ≤0.75 mm, upstaged with a re-biopsy, had a positive SLNB. After re-biopsy 8.5% underwent an increased surgical margin. Selective re-biopsy of partially sampled melanoma with gross residual disease can increase the accuracy of microstaging and optimize treatment regarding surgical margins and SLNB.

Melanoma and melanoma in-situ diagnosis after excision of atypical intraepidermal melanocytic proliferation: A retrospective cross-sectional analysis

BACKGROUND

There is little evidence to guide surgical management of biopsies yielding the histologic descriptor atypical intraepidermal melanocytic proliferation (AIMP).

OBJECTIVE

Determine frequency of and factors associated with melanoma and melanoma in-situ (MIS) diagnoses after excision of AIMP and evaluate margins used to completely excise AIMP.

METHODS

Retrospective, cross-sectional study of 1127 biopsies reported as AIMP and subsequently excised within one academic institution.

RESULTS

Melanoma (in situ, stage 1A) was diagnosed after excision in 8.2% (92/1127) of AIMP samples. Characteristics associated with melanoma/MIS diagnosis included age 60-79 years (odds ratio [OR] 8.1, 95% confidence interval [CI] 2.5-26.2), age ≥80 years (OR 7.2, 95% CI 1.7-31.5), head/neck location (OR 4.9, 95% CI 3.1-7.7), clinical lesion partially biopsied (OR 11.0, 95% CI 6.7-18.1), and lesion extending to deep biopsy margin (OR 15.1, 95% CI 1.7-136.0). Average ± standard deviation surgical margin used to excise AIMP lesions was 4.5 ± 1.8 mm.

LIMITATIONS

Single-site, retrospective, observational study; interobserver variability across dermatopathologists.

CONCLUSION

Dermatologists and pathologists can endeavor to avoid ambiguous melanocytic designations whenever possible through excisional biopsy technique, interdisciplinary communication, and ancillary studies. In the event of AIMP biopsy, physicians should consider the term a histologic description rather than a diagnosis, and, during surgical planning, use clinicopathologic correlation while bearing in mind factors that might predict true melanoma/MIS.

NEO412: A temozolomide analog with transdermal activity in melanoma in vitro and in vivo

Despite new treatments introduced over the past several years, metastatic melanoma remains difficult to cure. Although melanoma in situ (MIS) has better prognosis, it relies heavily on thorough surgical excision, where ill-defined margins can pose a challenge to successful removal, potentially leading to invasive melanoma. As well, MIS in the head and neck area can create serious aesthetic concerns with regard to the surgical defect and substantial scar formation. Toward improved treatment of localized melanoma, including the targeting of unrecognized invasive components, we have been studying a novel agent, NEO412, designed for transdermal application. NEO412 is a tripartite agent that was created by covalent conjugation of three bioactive agents: temozolomide (TMZ, an alkylating agent), perillyl alcohol (POH, a naturally occurring monoterpene with anticancer properties), and linoleic acid (LA, an omega-6 essential fatty acid). We investigated the anti-melanoma potency of NEO412 in vitro and in mouse models in vivo. The in vitro results showed that NEO412 effectively killed melanoma cells, including TMZ-resistant and BRAF mutant ones, through DNA alkylation and subsequent apoptosis. in vivo, NEO412 inhibited tumor growth when applied topically to the skin of tumor-bearing animals, and this effect involved a combination of increased tumor cell death with decreased blood vessel development. At the same time, drug-treated mice continued to thrive, and there was no apparent damage to normal skin in response to daily drug applications. Combined, our results present NEO412 as a potentially promising new treatment for cutaneous melanoma, in particular MIS, deserving of further study.

Current perspectives on Mohs micrographic surgery for melanoma

Mohs micrographic surgery (MMS), a specialized surgical excision technique used primarily in the treatment of skin cancers, is tissue sparing and provides optimal margin control through evaluation of 100% of both the peripheral and deep margin. The use of MMS for the treatment of malignant melanoma (MM) and melanoma in situ (MIS) has been slow in gaining the same widespread acceptance that it has for keratinocyte carcinomas despite its cost-effectiveness and the growing body of evidence demonstrating similar or improved cure rates to standard wide local excision. However, modern advances in immunohistochemical staining have continued to greatly enhance the ability of Mohs surgeons to interpret MMS frozen sections of melanoma specimens – the primary concern of most opponents of MMS for melanoma. These advances, coupled with an increased recognition by professional organizations of the utility of MMS in treating MM and MIS, have led to a rise in the use of MMS for melanoma in recent years. Given the expanding role of MMS in the treatment of cutaneous melanoma, this manuscript will describe how MMS is performed, discuss the rationale and current evidence regarding the use of MMS for MM and MIS, review the immunohistochemical stains currently available for use in MMS, and consider special situations and future directions in this area of growing interest.

A quantitative comparison between SOX10 and MART-1 immunostaining to detect melanocytic hyperplasia in chronically sun-damaged skin

Histologic differentiation of melanoma in situ (MIS) from solar keratosis on chronically sun-damaged skin is challenging. The first-line immunostain is usually MART-1/Melan-A, which can exaggerate the epidermal melanocytes, causing a diagnostic pitfall for MIS. By comparing MART-1 and SOX10 immunostaining, we scored the percentage of epidermal melanocytes per 2-mm diameter fields in pigmented actinic keratosis (n = 16), lichenoid keratosis (n = 7), junctional melanocytic nevus (n = 6), keratosis with atypical melanocytic proliferation (n = 17) and MIS (n = 10). These cases represented an older population (68 years median age) and the head and neck (50%) was the most common anatomic site. MART-1 score was significantly higher than SOX10 (P value <.05) in solar keratoses, but showed no difference in detecting melanocytic proliferations, demonstrating their equal detection rate of melanocytes. The sensitivity of both MART-1 and SOX10 was 100%, while their specificities were 17% and 96%, respectively. These results show that SOX10 is more specific than MART-1 in distinguishing epidermal melanocytes on sun-damaged skin by avoiding overdiagnosis of melanoma.

Melanoma in situ mimicking a Lichen planus-like keratosis

The incidence of melanoma has steadily increased over the past three decades. Melanoma in situ (MIS), defined as melanoma that is limited to the epidermis, contributes to a disproportionately high percentage of this rising incidence. Amelanotic melanoma presents as an erythematous macule or plaque and may initially be misdiagnosed as an inflammatory disorder. We report a case of amelonatic MIS raised on non-sun-exposed skin, inducing a lichen planus-like keratosis as inflammatory reaction, which clinically masked the melanoma. (www.actabiomedica.it)

Linear Malignant Melanoma In Situ: Reports and Review of Cutaneous Malignancies Presenting as Linear Skin Cancer

Melanomas usually present as oval lesions in which the borders may be irregular. Other morphological features of melanoma include clinical asymmetry, variable color, diameter greater than 6 mm and evolving lesions. Two males whose melanoma in situ presented as linear skin lesions are described and cutaneous malignancies that may appear linear in morphology are summarized in this report. A medical literature search engine, PubMed, was used to search the following terms: cancer, cutaneous, in situ, linear, malignant, malignant melanoma, melanoma in situ, neoplasm, and skin. The 25 papers that were generated by the search and their references, were reviewed; 10 papers were selected for inclusion. The cancer of the skin typically presents as round lesions. However, basal cell carcinoma and squamous cell carcinoma may arise from primary skin conditions or benign skin neoplasms such as linear epidermal nevus and linear porokeratosis. In addition, linear tumors such as basal cell carcinoma can occur. The development of linear cutaneous neoplasms may occur secondary to skin tension line or embryonal growth patterns (as reflected by the lines of Langer and lines of Blaschko) or exogenous factors such as prior radiation therapy. Cutaneous neoplasms and specifically melanoma in situ can be added to the list of linear skin lesions.

Melanoma in situ of penis: a very rare entity: A case report and review of the literature

RATIONALE

Melanoma in situ of the penis is very rare and there are no clear guidelines for its surgical treatment.

PATIENT CONCERNS

The authors describe the case of a 69-year-old man who presented with an asymptomatic brown macula on his glans penis and foreskin that appeared about 8 years earlier, enlarged in the last few months.

DIAGNOSES

A diagnostic biopsy showed the characteristics of a melanoma in situ.

INTERVENTIONS

The authors decided to excise the lesion keeping a healthy margin of 1 cm all over around except close to the urethral meatus, where it was impossible, and where only 5 mm of free margin was excised. A full thickness mucosal graft from oral cavity was performed to repair the defect.

OUTCOMES

No recurrence or metastasis occurred during 50 months after the operation.

LESSONS

Considering that at the sixth clinical follow-up the patient was alive and disease free at 50 months after surgery, the chosen treatment has proved successful.

A surgical perspective report on melanoma management

Management of melanoma includes wide excision with adequate margins and lymph node biopsy depending on the depth of the lesion, with subsequent completion lymphadenectomy for positive sentinel node. Locally advanced disease can be approached in several different ways depending on a variety of patient and disease-specific factors. These include surgical resection, isolated limb perfusion and infusion and intralesional injection therapy such as talimogene laherparepvec, IL-2 and Bacille Calmette-Guerin. Ongoing controversy exists regarding the utility of completion lymphadenectomy, and trials such as MSLT-2 will attempt to shed light on this issue. The future of melanoma management will likely focus on expanding the use of immunotherapy, allowing for narrower surgical margins, particularly in sensitive anatomic areas, and limiting the number of completion lymphadenectomies.

Clinical factors associated with subclinical spread of in situ melanoma

BACKGROUND

Subclinical spread of in situ melanoma occurs at a wide frequency, ranging from 12% to 71%.

OBJECTIVE

To identify clinical factors associated with subclinical spread of in situ melanoma.

METHODS

We used a retrospective, cross-sectional study of 674 consecutive in situ melanomas to examine 627 patients treated with Mohs surgery and melanoma antigen recognized by T cells 1 immunostaining. The presence of subclinical spread was correlated with clinical characteristics. Univariate and multivariate logistic regression analyses were performed to generate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Both univariate and multivariate analyses demonstrated significantly increased odds for subclinical spread of in situ melanomas when they were located on the head or neck, at acral sites, or on the pretibial leg (OR 1.97, 95% CI 1.41-3.40); in persons with a history of prior treatment (OR 2.77, 95% CI 1.74-4.420); melanomas of preoperative size >1 cm (OR 1.74, 95% CI 1.23-2.46, P = .002); or in persons ≥60 years old (OR 1.47, 95% CI 1.01-2.13, P = .042). A count prediction model demonstrated that the risk for subclinical spread increased with the number of clinical risk factors.

LIMITATION

We used a single-site, retrospective study design.

CONCLUSION

Clarifying the risk factors for subclinical spread might help to refine triage of in situ melanomas to the appropriate surgical techniques for margin assessment prior to reconstruction.

The use of Mohs micrographic surgery (MMS) for melanoma in situ (MIS) of the trunk and proximal extremities

BACKGROUND

Evaluation of the entire surgical margin results in high rates of complete excision, low local recurrence rates, and maximal tissue conservation. Although well recognized for melanoma of the head and neck, few studies have focused exclusively on the trunk and proximal extremities.

OBJECTIVE

We sought to evaluate the efficacy of Mohs micrographic surgery for melanoma in situ (MIS) of the trunk and proximal extremities, and determine adequate excision margins for MIS when total margin evaluation is not used.

METHODS

Long-term outcomes in 882 cases of MIS treated with Mohs micrographic surgery were analyzed and compared with historical controls. Rates of complete excision were determined for increasing surgical margin intervals.

RESULTS

One local recurrence occurred in our cohort (0.1%). Only 83% of MIS were excised with a 6-mm margin. Margins of 9 mm were needed to excise 97% of MIS, statistically equivalent to thin melanomas.

LIMITATIONS

We used a nonrandomized, single-institution, retrospective design.

CONCLUSION

Mohs micrographic surgery may cure the 17% of MIS that exceed traditional excision margins of 5 mm and is a valuable option for these patients. Surgical margins of at least 0.9 cm should be considered for MIS of the trunk and extremities when total margin evaluation is not used.

Trends in the diagnosis and clinical features of melanoma in situ (MIS) in US men and women: A prospective, observational study

BACKGROUND

The incidence of melanoma in situ (MIS) is increasing, but little is known about its clinical and epidemiologic features.

OBJECTIVE

We sought to determine trends in diagnosis and clinical features of MIS.

METHODS

Incident cases of melanoma were collected prospectively from the Nurses' Health Study (1976-2010) and Health Professionals Follow-up Study (1986-2010).

RESULTS

MIS incidence increased from 2 to 42 per 100,000 person-year among women, and from 11 to 73 per 100,000 person-year among men, exceeding the rate of increase of invasive melanomas. Melanoma mortality initially increased during the follow-up period then plateaued. Men were more likely than women to develop in situ melanomas on the upper half of the body (P < .001). Invasive melanomas were diagnosed at a younger age than MIS (P < .001), and were more likely to be found on the lower extremities than MIS (P < .001).

LIMITATIONS

This is a strictly descriptive study without examination into mechanisms.

CONCLUSION

We found epidemiologic and clinical differences for in situ and invasive melanomas, which support further examination into the variations in etiologic pathways. The lack of improvement in mortality despite the increase in detection of in situ relative to invasive lesions further highlights the need to improve invasive melanoma-specific clinical screening features.

Variation among pathologists' treatment suggestions for melanocytic lesions: A survey of pathologists

BACKGROUND

The extent of variability in treatment suggestions for melanocytic lesions made by pathologists is unknown.

OBJECTIVE

We investigated how often pathologists rendered suggestions, reasons for providing suggestions, and concordance with national guidelines.

METHODS

We conducted a cross-sectional survey of pathologists. Data included physician characteristics, experience, and treatment recommendation practices.

RESULTS

Of 301 pathologists, 207 (69%) from 10 states (California, Connecticut, Hawaii, Iowa, Kentucky, Louisiana, New Jersey, New Mexico, Utah, and Washington) enrolled. In all, 15% and 7% reported never and always including suggestions, respectively. Reasons for offering suggestions included improved care (79%), clarification (68%), and legal liability (39%). Reasons for not offering suggestions included referring physician preference (48%), lack of clinical information (44%), and expertise (29%). Training and caseload were associated with offering suggestions (P < .05). Physician suggestions were most consistent for mild/moderate dysplastic nevi and melanoma. For melanoma in situ, 18 (9%) and 32 (15%) pathologists made suggestions that undertreated or overtreated lesions based on National Comprehensive Cancer Network (NCCN) guidelines, respectively. For invasive melanoma, 14 (7%) pathologists made treatment suggestions that undertreated lesions based on NCCN guidelines.

LIMITATIONS

Treatment suggestions were self-reported.

CONCLUSIONS

Pathologists made recommendations ranging in consistency. These findings may inform efforts to reduce treatment variability and optimize patterns of care delivery for patients.

Discordance of histopathologic parameters in cutaneous melanoma: Clinical implications

BACKGROUND

Histopathologic analysis remains the gold standard for the diagnosis of melanoma, however previous studies have shown a substantial rate of interobserver variability in the evaluation of melanocytic lesions.

OBJECTIVE

We sought to evaluate discordance in the histopathological diagnosis and microstaging parameters of melanoma and subsequent impact on clinical management.

METHODS

This was a retrospective review of 588 cases of cutaneous melanoma and melanoma in situ from January 2009 to December 2014 that were referred to Emory University Hospital, Atlanta, GA, for treatment. Per institutional policy, all outside melanoma biopsy specimens were reviewed internally. Outside and institutional reports were compared.

RESULTS

Disagreement between outside and internal reports resulted in a change in American Joint Committee on Cancer pathologic stage in 114/588 (19%) cases, resulting in a change in management based on National Comprehensive Cancer Network guidelines in 105/588 (18%) cases.

LIMITATIONS

Given the retrospective nature of data collection and the bias of a tertiary care referral center, cases in this study may not be representative of all melanoma diagnoses.

CONCLUSION

These findings confirm consistent subjectivity in the histopathologic interpretation of melanoma. This study emphasizes that a review of the primary biopsy specimen may lead to significant changes in tumor classification, resulting in meaningful changes in clinical management.

Histopathology, treatment, and clinical management

Melanoma in situ (MIS) poses special challenges with regard to histopathology, treatment, and clinical management. The negligible mortality and normal life expectancy associated with patients with MIS should guide treatment for this tumor. Similarly, the approach to treatment should take into account the potential for MIS to transform into invasive melanoma, which has a significant impact on morbidity and mortality. Part II of this continuing medical education article reviews the histologic features, treatment, and management of MIS.

Epidemiology, screening, and clinical features

The incidence of melanoma has steadily increased over the past 3 decades, with melanoma in situ comprising a disproportionately high percentage of the rising incidence. Our understanding of melanoma in situ has been shaped by epidemiologic and clinical studies. Central to a review of melanoma in situ is a focus on its epidemiology, pathology, biologic behavior, treatment, and clinical outcome, which may differ significantly from that of malignant melanoma. Part I of this continuing medical education article reviews the epidemiology, risk factors, and clinical features of melanoma in situ; part II covers the histopathology, treatment options, and clinical management.

Lentigo maligna and lentigo maligna melanoma: contemporary issues in diagnosis and management

Lentigo maligna and lentigo maligna melanomas present diagnostic and treatment dilemmas due to their frequent presence within a background of sun-damaged skin, and their location on cosmetically and functionally sensitive areas. As the incidence of this entity is increasing, diagnostic and management controversies have developed. While surgery remains the gold standard of treatment, nonsurgical treatment options are also emerging for both adjunctive and primary therapy.

Risk of subsequent melanoma after melanoma in situ and invasive melanoma: a population-based study from 1973 to 2011

BACKGROUND

Patients with melanoma in situ are at an increased risk of subsequent melanoma compared with the general population, but the risk of subsequent melanoma after initial melanoma in situ versus after initial invasive melanoma is not known.

OBJECTIVE

We sought to compare the risk of subsequent melanoma in the cohort whose first cancer was melanoma in situ to the risk in the cohort whose first cancer was invasive melanoma.

METHODS

In this cohort study, we identified individuals whose first cancer was either melanoma in situ or invasive melanoma from the Surveillance, Epidemiology, and End Results (SEER) program between 1973 and 2011 and used Cox proportional hazards models for comparison.

RESULTS

Compared with the invasive melanoma cohort, the melanoma in situ cohort was more likely to develop subsequent melanoma of any stage after 2 years, subsequent invasive melanoma after 10 years, and subsequent melanoma in situ at all the time points (P < .001, P = .003, P < .001, respectively).

LIMITATIONS

Underreporting of melanomas, particularly melanoma in situ cases, and missing cases of subsequent melanomas as a result of patient migration from the SEER registry areas could affect results.

CONCLUSION

Given the increased long-term risk of subsequent melanoma in the melanoma in situ cohort, the patients with melanoma in situ diagnosis may benefit from a long-term surveillance for subsequent melanomas.