Lentigo Maligna Melanoma Research Articles

Unstable solar lentigo mimicking lentigo maligna melanoma: A case report

Solar lentigo (SL) is a hyperpigmented macule that develops due to chronic ultraviolet exposure. A 35-year-old housewife, presented with an asymptomatic pigmented patch on the right side of her nose for the last 10 years, with a rapid increase in size and variability in pigmentation over the last 3 years. She had no history of excessive sun exposure. Upon examination, there was a solitary, hyperpigmented, well to ill-defined patch of irregular shape and margin, measuring 3 cm * 2.5 cm, with variability in colour and areas of regression, almost covering Right side of nose. The patch appeared light brown with areas of dark brown and black. Differential diagnoses considered were Lentigo maligna melanoma (LMM), Solar Lentigo (SL), and flat seborrheic keratosis. Dermoscopy (Polarised illuco IDS-1100 dermoscope) revealed diffuse brown pigmentation with a faint pigmented network, along with dark brown to black globules and blotches. Due to the asymmetry of pigmentation, a punch biopsy was performed from the area of darkest pigmentation to rule out LMM. In Histology, the epidermis exhibited hyperkeratosis, follicular plugging, acanthosis, and downward elongation of the rete ridges. There was hyperpigmentation of the basal layer, an increased number of melanocytes, and the presence of melanophages in the papillary dermis. The biopsy report was consistent with Solar Lentigo (SL), and we concluded it as unstable solar lentigo (USL). This case is presented due to its clinical and dermoscopic resemblance to LMM and to increase awareness of USL and the importance of periodic surveillance.

Dermoscopy of atypical pigmented lesions of the face: Variation according to facial areas.

Atypical pigmented facial lesions (aPFLs)-including lentigo maligna (LM) and lentigo maligna melanoma (LMM), solar lentigo (SL), pigmented actinic keratosis (PAK), atypical nevi (AN), seborrheic keratosis (SK) and lichen planus-like keratosis (LPLK)-can exhibit clinical and dermoscopic overlapping features. We aimed to investigate if and how 14 dermoscopic features suggestive for the aforementioned aPFLs vary according to six facial sites among 1197 aPFLs cases (excised to rule out malignancy) along with lesion and patients' metadata. According to distribution and association analysis, aPFLs on the forehead of a male patient aged > 69 years displaying the obliterated follicular openings pattern, appear to be more at risk of malignancy. Of converse, aPFLs of the orbital/cheek/nose area with evident and regular follicular openings with diameter < 10 mm in a female aged below 68 are probably benign. The obliterated follicular openings, keratin plugs, evident and regular follicular openings and target-like pattern features differed significantly among six facial areas in all aPFLs cases. Lesion of the nose may show both features suggestive of malignancy and benignity (e.g. many SL and PAK may display target-like pattern and some LM/LMM cases display keratin plugs and evident and follicular openings), making these features less specific.

Sentinel lymph node biopsy for lentigo maligna melanoma under local anaesthesia.

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

The limited value of sentinel lymph node biopsy in lentigo maligna melanoma: A nomogram based on the results of 29 years of the nationwide dutch pathology registry (PALGA)

BackgroundLentigo maligna melanoma (LMM) predominantly presents in the head and neck of the elderly. The value of sentinel lymph node biopsy (SLNB) for LMM patients remains to be determined, as the reported average yield of positive lymph nodes is less than 10%. In this nationwide cohort study, we wanted to identify LMM patients with an increased risk of SLNB-positivity. MethodsLMM with an SLNB indication according to the 8th AJCC melanoma guidelines were retrospectively identified from the nationwide network and registry of histo- and cytopathology in the Netherlands (PALGA). A penalized (LASSO) logistic regression analysis was performed to determine the optimal combination of clinicopathological factors to predict a positive SLNB. ResultsBetween 1991 and 2020, 1989 LMM patients met our inclusion criteria. SLNB was performed in 16.7% (n = 333) and was positive in 7.5% (25/333). The false-negative rate was 21.9%. Clinically detectable regional lymph node (LN) metastases were found in 1.3% (n = 25). Clinicopathological characteristics best predictive for SLNB-positivity (Odds ratio; 95% CI) were age (0.95; 0.91–0.99), ulceration 1.59 (0.44–4.83), T4-stage (1.81; 0.43–6.2), male sex (1.97; 0.79–5.27), (lymph)angioinvasion (5.07; 0.94–23.31), and microsatellites (7.23; 1.56–32.7) (C-statistic 0.75). During follow-up, regional LN recurrences were detected in 4.2% (83/1989) of patients, of which the majority (74/83) had no evidence of regional LN metastases at baseline. ConclusionOur findings confirm the limited SLNB-positivity in LMM patients. Based on the identified high-risk clinicopathological features, a nomogram was developed to predict the risk of a positive SLNB.

Refining the application of PRAME-a useful marker in high CSD and acral melanoma subtypes.

Pathologic discordance affecting patient management may approach 20% in melanocytic cases following specialist review. The diagnostic utility of PRAME has been highlighted in several studies but interpretative challenges exist including its use in severely dysplastic compound nevi showing progression to melanoma in situ, nevoid melanoma, and coexisting nevi with melanoma. We examine the PRAME status of a broad spectrum of melanocytic lesions including challenging, dysplastic nevi with severe atypia from a large Irish patient cohort. Retrospective review of the dermatopathology database was conducted to evaluate the PRAME staining characteristics of two hundred and twenty-one melanocytic lesions using a commercially available PRAME antibody (EPR20330). The proportion of nuclear labeling and intensity of staining was recorded. The sensitivity and specificity of PRAME for in situ and malignant melanocytic lesions was 77% and 100%, respectively. Virtually all of our melanoma in situ from high-cumulative sun damaged (CSD) skin (22/23) and all acral lentiginous melanoma (5/5) were PRAME positive while 80% (8/10) of our lentigo maligna melanoma showed diffuse expression. None of our benign subgroup showed diffuse immunoexpression (0/82), including thirty-seven moderate or severely dysplastic nevi. In all cases of melanoma in situ arising in association with a dysplastic compound nevus (0/10), no immunoexpression was observed in the nevic component while in five cases of melanoma in situ with coexistent, intradermal nevus immunostaining was confined to the in situ component. A total of 100% (2/2) of desmoplastic melanomas and 50% (4/8) of nodular melanomas were PRAME positive. PRAME is a sensitive and highly specific immunostain in the diagnosis of in situ and invasive melanoma and we emphasize its application in the evaluation of high CSD and acral melanoma subtypes as well as in challenging threshold cases.

Lentigo maligna melanoma

Lentigo maligna melanoma is a relatively rare subtype of melanoma that appears de novo on the chronically sun-damaged skin of the elderly. Initially, it is a variably pigmented, sometimes amelanotic, slow-growing, irregular flat macule on the skin, which is melanoma in situ (lentigo maligna), and often persists for 10-15 years before developing into an invasive tumour. Dermoscopic examination in differentiating from other melanocytic and non-melanocytic lesions at early stage can be challenging. In many cases, the borders of the tumour cannot be determined precisely, not even histologically, which is why local recurrence is relatively common. In this paper, we present the specifics of the clinicopathological classification, dermoscopic differential diagnosis and treatment of lentigo maligna melanoma.

Melanoma-specific survival in worse in the elderly: a multicentric cohort study.

We aimed to characterise cutaneous melanoma in the elderly and determine its association with poorer prognosis. We studied a prospective cohort of the melanoma population in Catalonia between 2012 and 2016. We compared young patient group (<75 years old) with elderly patient group (≥75 years old). We included 3009 patients (52.5% women) from 14 centres, with a mean age at diagnosis of 61.1 years. In the ≥75-year-old group there was a predominance of men (53.9% vs. 45.5%, P < 0.001), melanoma was more frequently located in the head and neck area (37.7% vs. 15.5%, P < 0.001) and lentigo maligna melanoma subtype was significantly more frequent (31.4% vs. 11.6%, P < 0.001), as were nodular melanoma and acral lentiginous melanoma (P < 0.001). In older people, Breslow index, the presence of ulceration and mitotic rate were higher than in younger people. Kaplan-Meier survival curves showed longer melanoma specific survival (MSS) and melanoma-free survival (MFS) in <75-year-old group compared to the elderly group. Cox regression models demonstrated reduced MSS in patients ≥75 years regardless of gender, location, IB, ulceration and lymph node status at diagnosis (HR 1.54, P = 0.013) whereas MFS was not independently associated with elderly when head and neck location was considered. Age appears to be an independent risk factor for MSS but not for MFS. Worse melanoma prognosis in elderly could be explained by factors unrelated to the tumour, such as age-related frailty and comorbidities that limit the access to systemic treatments and, eventually, age-related immune dysfunction.

Prognosis in stageII melanoma of the head and neck depends on the histological subtype.

The melanoma guideline is mainly based on the AJCC stage. There is no difference according to histological subtypes such as superficial spreading melanoma (SSM), lentigo maligna melanoma (LMM) or nodular malignant melanoma (NM). We aimed to evaluate whether patients with LMM have a different clinical course from patients with SSM/NM. This is particularly important as adjuvant anti-PD-1 therapy is approved for stage IIB and IIC melanoma. Data were extracted from the Central Registry of Malignant Melanoma. Only patients with LMM, SSM, and NM of the head and neck with primary diagnosis between 01/01/2000 and 12/31/2019 were included. Progression-free survival (PFS), melanoma-specific survival (MSS), and pattern of metastases were analyzed for the LMM group compared to SSM/NM. The LMM cohort (n=902) had significantly better MSS than the SSM/NM cohort (n=604). There was no difference in PFS. The 5-year MSS of the stage II LMM cohort was 88.5% (95% CI 81.4-95.6) compared to 79.7% (95% CI 72.8-86.6) in the stage II SSM/NM cohort. It does not appear appropriate to use adjuvant therapy in stage II LMM patients to the same extent as in patients with SSM/NM.

Lentigo maligna and lentigo maligna melanoma in-vivo differentiation with dermoscopy and reflectance confocal microscopy: a retrospective, multi-center study.

Dermoscopic predictors of lentigo maligna (LM) and lentigo maligna melanoma (LMM) have been recently reported, but these have not been reported in reflectance confocal microscopy (RCM). (i) To validate dermoscopic predictors for LM/LMM, (ii) to identify RCM patterns in LM and LMM and (iii) correlations between dermoscopic and RCM features in LM and LMM. A retrospective, multicenter study of consecutive lesions with histologically proven LM or LMM subtypes of the head and face, with complete sets of dermoscopic and RCM images. A total of 180 lesions were included (n=40 LMM). Previously reported differential dermoscopic features for LM subtypes were confirmed. Other features significantly associated with LMM diagnosis included irregular hyperpigmented areas, shiny white streaks, atypical vessels, and light brown color at dermoscopy and medusa head-like structures, dermal nests and nucleated cells within the papillae at RCM (p<0.05). Correlations among LM lesions between dermoscopic and RCM features included brown to-gray dots and atypical cells (epidermis), grey color and inflammation and obliterated follicles and medusa head-like structures. Among LMM lesions, significant correlations included obliterated follicles with folliculotropism, both irregular hyperpigmented areas and irregular blotches with widespread atypical cell distribution (epidermis), dermal nests and nucleated cells within the papillae (dermis). Irregular blotches were also associated with medusa head-like structures (dermal epidermal junction [DEJ]). Dermoscopic and RCM features can assist in the in-vivo identification of LM histopathological subtypes and many are correlated. RCM 3-dimensional analysis of skin layers allows the identification of invasive components in the DEJ and dermis.

Immunohistochemical detection of the chondroitin sulfate proteoglycan 4 protein in primary and metastatic melanoma.

Treatment of malignant melanoma, the most aggressive form of skin cancer, continues to be a major challenge for clinicians. New targeted therapies with kinase inhibitors or drugs which modify the immune response are often accompanied by the development of resistance or severe side effects. In this context, chondroitin sulfate proteoglycan 4 (CSPG4), a highly immunogenic melanoma tumor antigen, could be a potential target for alternative therapeutic approaches. The aim of the present study was to identify differences in the levels of CSPG4 protein expression in primary and metastatic melanomas as well as to analyze correlations between CSPG4 expression and histopathological data and patient characteristics. A total of 189 melanoma tissue samples from Lower Austria, including primary melanomas and melanoma metastases, were immunohistochemically stained for the expression of CSPG4 and statistical analyses were performed. A total of 65.6% of melanoma tissue samples stained positive for the expression of CSPG4. Primary nodular and primary superficial spreading melanomas demonstrated a significantly higher number of positively stained tissue samples for CSPG4 compared with primary lentigo maligna melanomas. No significant differences in the expression of CSPG4 were demonstrated between primary melanomas and melanoma metastases. The present study supports the advancement of the understanding of CSPG4 tissue expression patterns in melanoma patients and provides additional information for further investigation of CSPG4 as a potential therapeutic target.

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

Most surgical margins for lentigo maligna melanomas reported in the literature are clinical and not histologic. We sought to determine whether histologic margin status is an independent predictor of progression. Clinicopathologic information of 268 invasive lentigo maligna melanomas diagnosed from 1990-2019 were analyzed. Statistical analyses were performed using Cox proportional hazards model and Boruta method. A total of 75% of the lesions were located on the head and neck. The range of follow-up for all patients was 0 to 31.8years (median, 10.2years). Time to local recurrence ranges from 0 to 20years (median, 3years). Progression developed in 54 (20.1%) of 268 patients. Local recurrence was seen only in 36 (13.4%), both local recurrence and subsequent metastasis in 7 (2.6%), and only metastasis in 11 (4.1%) of 268 patients. Histologic margin status (positive and close/<3mm) and tumor site (head and neck location) significantly correlated with worse progression-free survival. Single institution and retrospective study. Histologic margin status is the strongest predictor of progression for lentigo maligna melanoma. Patients with positive or close/<3mm histologic margins should consider a re-excision due to the increased risk of relapse.

Malignant Melanoma in a Retrospective Cohort of Immunocompromised Patients: A Statistical and Pathologic Analysis.

Malignant melanoma is the leading cause of death due to cutaneous malignancy. Immunocompromised individuals have an elevated risk of developing melanoma. We aimed to provide histopathologic and statistical characterization of melanoma development in immunocompromised patients. We reviewed our institution's databases to identify all patients with a confirmed history of immunosuppression who subsequently developed melanoma, focusing on diagnoses during the follow-up period of 2011-2019. A total of 93 patients with a combined 111 melanoma lesions were identified. Common causes of immunosuppression included transplantation and lymphoproliferative disorders. Superficial spreading and lentigo malignant melanoma were the most common malignant melanoma subtypes. Median Breslow depth was 0.7 mm, and the most common primary tumor stage was T1a. Our transplant sub-cohort had an overall melanoma incidence of 0.9 per 1000 person-years (95% CI 0.66 to 1.20) and a standardized incidence ratio (SIR) of 1.53 (95% CI 1.12 to 2.04) relative to a general population cohort from the Surveillance, Epidemiology, and End Results Program (SEER). We report histopathologic characteristics of immunocompromised patients developing melanoma at a large academic tertiary-care center. Differences in age, sex, time since transplantation, and transplant type may play a significant role in melanoma SIR in this patient demographic.

Clinicopathological Features of 106 Cases of Chinese Patients with Acral Melanoma

Cutaneous melanoma is usually classified mainly into four main histological subtypes: superficial spreading melanoma (SSM), lentigo maligna melanoma (LMM), nodular melanoma (NM)

DS03 Lentigo maligna: is it time to put down the scalpel?

Abstract Lentigo maligna (LM) is a subtype of melanoma in situ that often proves to be a diagnostic and therapeutic challenge. Treatment aims to prevent progression to an invasive tumour called lentigo maligna melanoma (LMM). In the UK, common treatment modalities include conventional excision, staged re-excisions, slow Mohs surgery or expectant monitoring. Although considered the ‘gold standard’, surgical excision of LM can be disfiguring as it frequently affects cosmetically sensitive areas requiring complex surgical reconstructions. Topical imiquimod 5% presents a pragmatic alternative treatment modality without the need for surgery. In vivo reflectance confocal microscopy (RCM) allows real-time noninvasive delineation of LM. Evidence suggests this is an effective diagnostic tool for pre- and post-treatment evaluation (Brand FL, Jafari SM, Hunger RE. Confocal microscopy and lentigo maligna: an in vivo pilot study for the assessment of response to imiquimod therapy. Dermatology 2019; 235:150–5). We retrospectively analysed 35 cases of histologically confirmed LM that completed treatment with imiquimod between 2018 and 2022. The average patient age at diagnosis was 73.9 years, with a female : male ratio of 18 : 17. Following assessment with RCM, patients were prescribed a protocol of topical imiquimod 5% once a day, 5 days per week for 12 weeks, along with instructions to apply this 10 mm beyond the mapped area or a cosmetic unit (Australia and New Zealand Melanoma Trials Group RADICAL trial). Patients were counselled about expected side-effects; all completed the course and achieved significant inflammation and superficial ulceration. To ensure a response was achieved, the following stepwise interventions were used: application increased to 7 days per week, occlusion with a dressing and addition of a topical retinoid. Repeat RCM was performed 6 months after treatment completion. At this point, 30 of 35 (86%) patients responded with no evidence of residual LM on RCM. Three cases required a second course of treatment. Two of these were shown to be clear on RCM, while the third is clinically clear and awaiting RCM confirmation. A fourth patient was lost to follow-up. A further patient has failed two courses and is about to embark on a third round of treatment. In total, 16 cases completed the 12-month review and maintained clearance. We demonstrate that imiquimod is an effective treatment for LM, potentially avoiding extensive surgery and complex reconstruction. Reflectance confocal microscopy can be used to delineate the extent of the LM and assess the post-treatment response. Our preliminary data suggest a significant proportion of LM cases achieved clearance with no recurrences to date. Follow-up of these patients will help evaluate the long-term efficacy of imiquimod, but our data suggest this treatment protocol provides a promising alternative to surgical intervention.

The role of histological subtypes in the survival of patients diagnosed with cutaneous or mucosal melanoma in the United States of America.

Literature presents limited information on histological subtypes and their association with other factors influencing the survival of melanoma patients. To explore the risk of death due to melanoma associated with histological subtypes, this retrospective study used the Surveillance, Epidemiology, and End Results program (SEER) data from 1998 to 2019. A total of 27,532 patients consisting of 15,527 males and 12,005 females. The Hypertabastic Accelerated Failure Time model was used to analyze the impact of histology on the survival of patients with cutaneous or mucosal melanoma. The median survival time (MST) for cutaneous patients was 149 months, whereas those diagnosed with mucosal melanoma was 34 months. Nodular melanoma had a hazard ratio of 3.40 [95% CI: (2.94, 3.94)] compared to lentigo maligna melanoma. Across all histological subtypes, females had a longer MST, when compared to males. The hazard ratio (HR) of distant to localized melanoma was 9.56 [95% CI: (7.58, 12.07)]. Knowledge of patients' histological subtypes and their hazard assessment would enable clinicians and healthcare providers to perform personalized treatment, resulting in a lower risk of complication and higher survivability of melanoma patients. Significant factors were stage of the disease, age, histology, sex, and income. Focus should be placed on high-risk populations with severe and aggressive histological subtypes. Programs that emphasize preventive measures such as awareness, education, and early screening could reduce risk.

Clinicopathological Profile of a Cohort of Patients With Malignant Melanoma in the United Kingdom.

Introduction Malignant melanoma (MM) is potentially a fatal type of skin cancer and a major health concern for the Caucasian population. It is a heterogeneous disease with a wide spectrum of manifestations. Therefore, in this study, we evaluated the clinicopathological characteristics of MM. Methods We retrospectively studied the clinicopathological characteristics of MM in 167 biopsy-proven cases of MM reported between January 2020 and December 2021 at Kings Mill Hospital, Sutton-in-Ashfield, United Kingdom. Clinical data such as the age, sex, and anatomical site of the lesion were obtained from the clinical referral forms. Biopsies of the lesions were performed, and the specimens collected were sent to the laboratory for histopathological study and v-raf murine sarcoma viral oncogene homolog B1 (BRAF) mutation evaluation. Formalin-fixed paraffin-embedded blocks (FFPE) were prepared, sectioned, and stained with hematoxylin and eosin for histological examination. Results A total of 167 cases of MM were included in the study. The age range was 23-96 years, with the median age at diagnosis found to be 66 years; males were more commonly affected (52.1%). The median Breslow thickness was 1.20 mm. The median mitotic activity was 1.0/mm2. The lower limb was the most common site of involvement (27.5%), followed by the thorax (25.1%). The most common histological subtype was superficial spreading melanoma (SSM) (77.8%), followed by nodular melanoma (14.4%). The in situ component was present in 95.8% of cases; a majority (92.2%) of the cases showed vertical growth phase, 71.9% of cases were at Clark's level IV of invasion, regression was noted in 70.7% of cases, ulceration was present in 21.6% of cases, and microsatellites were present in 3% of cases. Perineural invasion was present in 3% of cases, and lymphovascular invasion (LVI) was present in 4.2% of cases. BRAF mutation testing was performed on 36 cases, out of which 20 cases (55.6%) showed BRAF mutation. Acral lentiginous melanoma and nodular melanoma were most likely to show ulceration (66.7% and 37.5%, respectively). SSM and lentigo maligna melanoma were more likely to be associated with regression. Conclusion The study demonstrated that MM is prevalent among the elderly population with male predominance; SSM was found to be the most common subtype. The study further demonstrated various clinicopathological features of MM and its association with histological subtypes.

Efficacy of imiquimod in the management of lentigo maligna.

Lentigo maligna (LM) is a melanocytic proliferation occurring on photo-exposed skin that may progress to LM melanoma. Surgery is recommended as first-line treatment. Excision margins of 5-10 mm remain, without international consensus. Several studies have shown that imiquimod, an immunomodulator, induces LM regression. This study investigated the effect of imiquimod versus placebo in neoadjuvant settings. We performed a prospective, randomized, multicentre, phase III clinical study. Patients were randomly assigned in 1:1 ratio to receive imiquimod or placebo for 4 weeks, followed by LM excision 4 weeks after the last application of imiquimod or placebo. The primary endpoint was extra-lesional excision, with a 5 mm margin from the residual pigmentation after imiquimod or vehicle. Secondary endpoints included the gain on the surface removed between the two groups; number of revision surgeries to obtain extra-lesional excisions; relapse-free time; and number of complete remissions after treatment. A total of 283 patients participated in this study; 247 patients, 121 patients in the placebo group and 126 in the imiquimod group, accounted for the modified ITT population. The first extralesional extirpation was performed in 116 (92%) imiquimod patients and in 102 (84%) placebo patients; the difference was not significant (p = 0.0743). Regarding the surface of LM, imiquimod reduced the LM surface (4.6-3.1 cm2 ) significantly (p < 0.001) more compared to the placebo (3.9-4.1 cm2 ). Imiquimod reduces the lentigo maligna surface after 1 month of treatment, without a higher risk of intralesional excision and with a positive aesthetic outcome.

Surgical margin mapping for lentigo maligna and lentigo maligna melanoma: traditional technique (visual inspection with dermoscopy) versus combined paper tape and reflectance confocal microscopy technique.

The detection of subclinical margin in lentigo maligna/lentigo maligna melanoma (LM/LMM) can be challenging for the dermatologist. Reflectance confocal microscopy (RCM) enables to observe in vivo atypical melanocytes beyond the clinical margins. The aim of this study is to establish which of these methods (clinical examination and dermoscopy versus "Paper tape - RCM") is more precise to define the lesion margin and to reduce the number of re-intervention and overtreatments in cosmetically sensitive areas. Fifty-seven cases of LM/LMM were analyzed during 2016-2022. Pre-surgical mapping procedures in 32 lesions were effectuated with dermatoscopy. Furthermore, pre-surgical mapping procedures in 25 lesions were effectuated with RCM and paper tape. RCM method's accuracy to detect subclinical margins was 92.0%. In 24 of 25 cases, the lesions were excised completely during the first intervention. In 20 of 32 cases analyzed with dermoscopy, a second surgical intervention was effectuated. The RCM paper method allows us to delineate subclinical margin more accurately and reduce overtreatment, especially in sensitive areas, such as the face and neck.

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

Melanoma guidelines recommend surgical excision with 10-mm margins for T1 melanoma. However, this procedure may be problematic at sites close to critical structures such as the scalp, face, external genitalia, acral, periumbilical, and perineal areas. To compare outcomes of wide (10-mm margins) vs narrow (5-mm margins) excision in patients with T1a melanoma near critical structures. This cohort study was a retrospective comparison of 1341 consecutive patients aged 18 years or older from the National Cancer Institute of Milan, Italy, diagnosed between 2001 and 2020 with T1a cutaneous melanoma close to critical structures who accepted wide excision vs narrow excision. Local recurrence and melanoma-specific mortality (MSM) rates with 5-mm vs 10-mm excision margins. The primary aim of the study was to ascertain whether a narrower (5-mm) vs wider (10-mm) excision margin was associated with local recurrence and MSM. The secondary aim was to compare the need for reconstructive surgery in the groups defined by excision margin width. Between April 28 and August 7, 2022, associations were assessed by weighted Cox and Fine-Gray univariable and multivariable models. A total of 1179 patients met the inclusion criteria (median [IQR] age, 50.0 [39.5-63.0] years; female, 610 [51.7%]; male, 569 [49.3%]). Six hundred twenty-six patients (53.1%) received a wide excision (434 [69.3%] with linear repair and 192 [30.7%] with flap or graft reconstruction) and 553 (46.9%) received a narrow excision (491 [88.8%] with linear repair and 62 [11.2%] with flap or graft reconstruction). The weighted 10-year MSM was 1.8% (95% CI, 0.8%-4.2%) in the wide group and 4.2% (95% CI, 2.2%-7.9%) in the narrow group; the weighted 10-year local recurrence rate was 5.7% (95% CI, 3.9%-8.3%) in the wide group and 6.7% (95% CI, 4.7%-9.5%) in the narrow group. Breslow thickness greater than 0.4 mm (subdistribution hazard ratio [sHR] for 0.6 vs 0.4 mm, 2.42; 95% CI, 1.59-3.68; P < .001) and mitotic rate greater than 1/mm2 (sHR for a single increment, 3.35; 95% CI, 2.59-4.32; P < .001) were associated with worse MSM. Multivariable analysis showed that acral lentiginous melanoma, lentigo maligna melanoma, and increasing Breslow thickness were associated with a higher incidence of local recurrence. The study's findings suggest that local excision with 5-mm margins for T1a melanoma may not be associated with an increased risk of local recurrence. Breslow thickness greater than 0.4 mm, mitotic rate greater than 1/mm2, and acral lentiginous melanoma and lentigo maligna melanoma subtypes were associated with a higher risk of recurrence. These findings may be useful for future melanoma treatment guidelines.

Similar local recurrence and survival in patients with T1 radial growth phase melanoma on head and neck treated with 5 or 10 mm margins: A retrospective study.

Melanoma guidelines recommend surgical excision with 10 mm margins for T1 melanomas (invasive melanomas with Breslow thickness ≤1 mm), including those in radial growth phase, which are without metastatic potential; however, such margins may be problematic on head-and-neck. We compared outcomes of wide (10 mm margins) versus narrow (5 mm margins) excisions in patients with radial growth phase T1 melanoma on head-and-neck including face. We retrospectively examined 610 consecutive patients excised with wide versus narrow margins, from 2001 to 2018, at six European centres. In all cases, radial growth phase, and clear margins with 5 or 10 mm of clearance, were ascertained histologically. Multivariable models investigated associations of margins and other factors with overall survival and local recurrence. Three hundred and sixteen (51.8%) patients received wide excision, 219 (69.3%) with primary wound closure, 97 (30.7%) with reconstruction; 294 (48.2%) patients received narrow excision, 264 (89.8%) with primary wound closure, 30 (10.2%) with reconstruction (p < 0.001). Median follow-ups were 88 months (wide) and 187 months (narrow) (inter-quartile ranges 43-133 and 79-206, respectively). Ten-year overall survival (95% confidence interval) was 96.7% (94.2%-99.3%) in wide and 98.2% (96.4%-100%) in narrow patients. Ten-year local recurrence incidence was 6.4% (4.1%-10.1%) in wide and 7.8% (5.3%-11.6%) in narrow groups. Lentigo maligna melanoma subtype appeared associated with increased risk of local recurrence in narrow versus wide patients (15.0% vs. 7.5%; p=0.190). Narrower excision margins for T1 radial growth phase melanoma are not associated with worse overall survival (hazard ratio 0.97, p=0.996) or increased local recurrence (subdistribution hazard ratio: 0.87; p=0.751) compared to wider margins, and may be safely applied to such lesions, although caution may be required in the presence of lentigo maligna melanoma.