Is sentinel lymph node biopsy needed for lentigo maligna melanoma?

BACKGROUND AND OBJECTIVES: Sentinel lymph node biopsy (SLNB) is an area of debate in the management of lentigo maligna melanoma (LMM). The utility of SLNB and its prognostic value in LMM have not yet been studied with large databases. METHODS: We performed a retrospective review of the National Cancer Database (2012-2020) and the Surveillance, Epidemiology, and End Results (2010-2019) database for patients with cutaneous nonmetastatic LMM with Breslow thickness >1.0 mm. Multivariable logistic regression identified factors associated with SLNB performance and sentinel lymph node (SLN) positivity. Univariable and multivariable analyses assessed overall survival (OS) and melanoma-specific survival (MSS) based on SLNB performance and SLN status. RESULTS: Compared to other melanoma subtypes, LMM had lower rates of SLNB (66.6% vs. 80.0%-84.0%) and SLN positivity (11.3% vs. 18.6%-34.2%). Compared to patients who did not undergo SLNB, SLN status was significantly associated with improved OS in patients with SLN positive (HR = 0.64 [0.55-0.76]) and SLN negative (HR = 0.68 [0.49-0.94]), and worse MSS only in patients with positive SLN (HR = 3.93, p < 0.05). CONCLUSION: The improved OS associated with SLNB likely implies surgical selection bias. Analysis of MSS confirms appropriate patient selection and suggests important prognostic value associated with SLN status. These results support continued SLNB for LMM patients according to standard guidelines.

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

BACKGROUND: Lentigo maligna (LM) can mimic benign, flat, pigmented lesions and can be challenging to diagnose. OBJECTIVE: To describe a new dermatoscopic feature termed "perifollicular linear projections (PLP)" as a diagnostic criterion for LM on the face. METHODS: Retrospective study on reflectance confocal microscopy and dermatoscopy images of flat facial pigmented lesions originating from 2 databases. PLP were defined as short, linear, pigmented projections emanating from hair follicles. Dermatoscopy readers were blinded to the final histopathologic diagnosis. RESULTS: From 83 consecutive LMs, 21/83 (25.3%) displayed "bulging of hair follicles" on reflectance confocal microscopy and 18 of these 21 (85.7%), displayed PLP on dermatoscopy. From a database of 2873 consecutively imaged and biopsied lesions, 252 flat-pigmented facial lesions were included. PLP was seen in 47/76 melanomas (61.8%), compared with 7/176 lesions (3.9%) with other diagnosis (P < .001). The sensitivity was 61.8% (95% CI, 49.9%-72.7%), specificity 96.0% (95% CI, 92.9%-98.4%). PLP was independently associated with LM diagnosis on multivariate analysis (OR 26.1 [95% CI, 9.6%-71.0]). LIMITATIONS: Retrospective study. CONCLUSION: PLP is a newly described dermatoscopic criterion that may add specificity and sensitivity to the early diagnosis of LM located on the face. We postulate that PLP constitutes an intermediary step in the LM progression model.

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.

Real-life practice of reflectance confocal microscopy in France: A prospective multicenter study.

BACKGROUND: Studies demonstrating the potential utility of reflectance confocal microscopy (RCM) have been performed under experimental conditions. OBJECTIVE: To provide an overview of RCM practice in real-life. METHODS: A multicenter, prospective study carried out in 10 university dermatology departments in France. RESULTS: Overall, 410 patients were enrolled. One-half of the patients (48%) were referred by private practice dermatologists. They were referred for diagnosis (84.9%) or presurgical mapping (13%). For diagnosis, the lesions were located on the face (62%), arms and legs (14.9%), and trunk (13.6%), and presurgical mapping was almost exclusively on the face (90.9%). Among those referred for diagnosis, the main indication was suspicion of a skin tumor (92.8%). Of these, 50.6% were spared biopsies after RCM. When RCM indicated surgery, histology revealed malignant lesions in 72.7% of cases. The correlation between RCM and histopathology was high, with a correlation rate of 82.76% and a kappa coefficient of 0.73 (0.63; 0.82). LIMITATIONS: This study was performed in the settings of French tertiary referral hospitals. CONCLUSION: This study shows that in real-life RCM can be integrated into the workflow of a public private network, which enables a less invasive diagnostic procedure for patients.

Extrafacial lentigo maligna: A progression model and enhanced diagnostic techniques using dermatoscopy and reflectance confocal microscopy.

Lentigo maligna (LM) is a subtype of lentiginous melanoma confined to the epidermis, which is associated with chronic sun exposure. Its clinical, dermatoscopic, and histopathological diagnosis can be challenging, particularly in the early and advanced stages, requiring appropriate clinicopathological correlation. This article reviews the clinical presentation, diagnosis through noninvasive methods (dermoscopy and confocal microscopy), and provides insights for diagnosis of extrafacial LM through the presentation of four representative clinical cases from different phases of a theoretical-practical progression model. Recognizing these lesions is crucial, as once they invade the dermis, they can behave like any other type of melanoma.

Dermoscopy of Lentiginous Melanomas and Equivocal Benign Pigmented Macules of the Scalp: A Case-Control Multicentric Study.

INTRODUCTION: Although the dermoscopic features of facial lentiginous melanomas (LM), including lentigo maligna and lentigo maligna melanoma, have been extensively studied, the literature about those located on the scalp is scarce. This study aims to describe the dermoscopic features of scalp LM and assess the diagnostic accuracy of dermoscopy to discriminate them from equivocal benign pigmented macules. METHODS: Consecutive cases of scalp LM and histopathology-proven benign but clinically equivocal pigmented macules (actinic keratoses, solar lentigos, seborrhoeic keratoses, and lichen planus-like keratoses) from four referral centres were included. Dermoscopic features were analysed by two blinded experts. The diagnostic performance of a predictive model was assessed. RESULTS: 56 LM and 44 controls were included. Multiple features previously described for facial and extrafacial LM were frequently identified in both groups. Expert's sensitivity to diagnose scalp LM was 76.8% (63.6-87.0) and 78.6% (65.6-88.4), with specificity of 54.5% (38.9-69.6) and 56.8% (41.0-71.7), and fair agreement (kappa coefficient 0.248). The strongest independent predictors of malignancy were (OR, 95% CI) chaos of colour (15.43, 1.48-160.3), pigmented reticular lines (14.96, 1.68-132.9), increased density of vascular network (3.45, 1.09-10.92), and perifollicular grey circles (2.89, 0.96-8.67). The predictive model achieved 85.7% (73.8-93.6) sensitivity, 61.4% (45.5-75.6) specificity, and 81.5 (73.0-90.0) area under curve to discriminate benign and malignant lesions. A diagnostic flowchart was proposed, which should improve the diagnostic performance of dermoscopy. CONCLUSION: Both facial and extrafacial dermoscopic patterns can be identified in scalp LM, with considerable overlap with benign pigmented macules, leading to low specificity and interobserver agreement on dermoscopy.

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.

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

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

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

BACKGROUND: Lentigo maligna/lentigo maligna melanoma (LM/LMM) can present with subclinical extension that may be difficult to define preoperatively and lead to incomplete excision and potential recurrence. Preliminarily studies have used reflectance confocal microscopy (RCM) to assess LM/LMM margins. OBJECTIVE: To evaluate the correlation of LM/LMM subclinical extension defined by RCM compared with the gold standard histopathology. METHODS: Prospective study of LM/LMM patients referred for dermatologic surgery. RCM was performed at the clinically defined initial surgical margin followed by margin-controlled staged excision with paraffin-embedded tissue, and histopathology was correlated with RCM results. RESULTS: Seventy-two patients were included. Mean age was 66.8 years (standard deviation, 11.1; range, 38-89); 69.4% were men. Seventy of 72 lesions (97.2%) were located on the head and neck with mean largest clinical diameter of 1.3 cm (range, 0.3-5). Diagnostic accuracy for detection of residual melanoma in the tumor debulk (after biopsy) had a sensitivity of 96.7% and a specificity of 66.7% when compared with histopathology. RCM margin assessment revealed an overall agreement with final histopathology of 85.9% (κ = 0.71; P < .001). LIMITATIONS: No RCM imaging beyond initial planned margins was performed. CONCLUSION: RCM showed moderate to excellent overall agreement between RCM imaging of LM/LMM and histopathology of staged excision margins.

Understanding melanoma in situ: Lentigo maligna surgical treatment terminology and guideline adherence, a targeted review.

BACKGROUND: Malignant melanoma in-situ, lentigo maligna (MMIS-LM) can be successfully treated with several different surgical techniques; however, the literature is inconsistent in defining them. OBJECTIVE: To comprehensively define and describe the national guideline recommended surgical techniques used to treat MMIS-LM to help clarify and standardize this terminology to ensure compliance with the guidelines. METHODS: A targeted literature review was performed from 1990 to 2022 focusing on articles that discussed the national guideline recommended surgical techniques of wide local excision, Mohs micrographic surgery (MMS), modified Mohs surgery, and staged excision/Slow-Mohs for MMIS-LM, as well as the related methods of tissue processing. National Comprehensive Cancer Network and American Academy of Dermatology guidelines were reviewed to identify how the techniques need to be employed to be compliant with guideline recommendations. RESULTS: We describe the various surgical and tissue processing techniques and discuss advantages and disadvantages of each. LIMITATIONS: This paper was styled as a narrative review defining and clarifying terminology and technique and does not investigate these topics more broadly. CONCLUSION: Understanding the methodology and terminology for these surgical procedures and tissue processing methods is critical so that both general dermatologists and surgeons can employ these techniques effectively for optimal patient care.

Line-field confocal optical coherence tomography of lentigo maligna with horizontal and vertical histopathologic correlations.

Lentigo maligna (LM) is a subtype of in situ melanoma that classically presents in elderly patients as a slowly growing lesion on sun-exposed areas that may evolve to invasive melanoma. Line-field confocal optical coherence tomography (LC-OCT) is a new non-invasive technique for a real-time, vertical, and horizontal skin imaging with high resolution close to conventional histopathology. We present the LC-OCT features of an LM of the nose in a 49-year-old white man along with their horizontal and vertical histopathological correlations. LC-OCT was able to detect in vivo, in both horizontal and vertical imaging, the main microscopic features typical of LM by showing, in the epidermis and around the hair follicles, the presence of large, bright roundish, or dendritic atypical cells, with evident nuclei, corresponding to atypical melanocytes with a tendency toward folliculotropism. A strong correspondence between LC-OCT images and vertical and horizontal histopathological sections was observed. Our study, although limited to a single case, is indicative of the great potential of LC-OCT to improve the non-invasive diagnosis of LM.

Periocular invasive melanoma manifestation in a patient using bimatoprost: case report and literature review.

Prostaglandin F2a analogs (PGAs) are considered efficacious in the first-line treatment of glaucoma. They have however been associated with a number of periocular side effects. We present a case of periocular hyperpigmentation and progression to lentigo maligna melanoma (LMM) in a patient using bimatoprost eye drops. We conducted a literature review regarding the etiology and pathophysiology of periocular pigmentation in this setting.A 71-year-old female Caucasian patient with open-angle glaucoma using bimatoprost exclusively in her right eye noticed an ipsilateral lower eyelid/upper cheek area dark lesion after commencing treatment. Examination demonstrated a heterogeneously pigmented lesion. Excisional biopsy demonstrated extensive lentigo maligna (melanoma in situ) with superficially invasive malignant melanoma in the lesion center. The patient underwent successful staged excision and reconstruction. Literature review has demonstrated case reports supporting periocular hyperpigmentation; however, there has been no description of progression to periocular lentigo maligna and melanoma in a patient using bimatoprost.

Update on Lentigo Maligna: Diagnostic Signs and Treatment. / El lentigo maligno: actualización y claves en el diagnóstico y el tratamiento.

Lentigo maligna is an in situ cutaneous melanoma that arises in sun-damaged skin. Its most common presentation is a progressive, slow-growing, irregularly pigmented spot on the face of older patients. Although the exact percentage of Lentigo maligna that progresses to invasive tumors is unknown, it is thought to lie between 2% and 5%. Both the clinical and histologic diagnosis of Lentigo maligna can be challenging, especially in patients with early-stage or atypical disease. Treatment also holds challenges, because lesions are located in highly visible areas and are often large. Surgery can thus compromise cosmetic and sometimes functional outcomes. We review clinical and histopathological findings that can facilitate the diagnosis of Lentigo maligna. We also examine treatment options, with a focus on surgery.

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.

Fluorescence-advanced videodermatoscopy (FAV) for the differential diagnosis of suspicious facial lesions: A single-centre experience with pattern analysis and histopathological correlation.

BACKGROUND: Fluorescence-advanced videodermatoscopy (FAV) is a new non-invasive high-resolution skin imaging technique to assess pigmented lesions in conjunction with the clinical examination and dermatoscopy. OBJECTIVES: This is the first prospective study to identify morphologic descriptors and standardized terminology to examine facial pigmented lesions using FAV. The objectives were to identify FAV indicators, which can assist physicians in diagnosing suspicious flat facial pigmented lesions. METHODS: Consecutive equivocal pigmented lesions were retrospective analysed. Histopathological examination was performed for all the lesions. The main cytomorphological and cytoarchitectural FAV features were described and correlated with histopathological characteristics. RESULTS: From January to October 2020, 21 consecutive clinically suspected pigmented lesions in 20 patients were analysed using dermatoscopy and FAV and then surgically excised. Histopathological examination identified lentigo maligna (LM), lentigo maligna melanoma (LMM), solar lentigo (SL), flat seborrheic keratosis (SK) and pigmented actinic keratosis (PAK). Thirteen malignant melanocytic lesions were removed (11 LM, 2 LMM), two were diagnosed as PAK, and the remaining six pigmented lesions were SL-SKs. With FAV, large ovoid pleomorphic and dendritic cells arranged in the intrafollicular disposition, are typical of most malignant melanocytic lesions (12/13, 92.3%). No benign lesions displayed these features. In dermatoscopy, this folliculotropism corresponded to the presence of an annular-granular pattern with slate grey dots that were aggregated asymmetrically around follicular openings. CONCLUSIONS: FAV features can provide an improved diagnostic approach in the differential diagnosis of flat pigmented facial lesions.

Clinical findings are not helpful in detecting lentigo maligna melanoma in patients with biopsy-proven lentigo maligna.

BACKGROUND: Lentigo maligna (LM) based on biopsy material might be lentigo maligna melanoma (LMM) after excision. OBJECTIVES: Investigate whether clinical and dermoscopic mapping increases the detection rate of LMM when investigating staged excision specimens of biopsy proven LM. METHODS: Patients with biopsy-proven LM planned for staged excision were included. Using clinical inspection and dermoscopy, spots suspicious for LMM were marked. After the excision, needles were placed at the marked spots. Histological examination using vertical sections was done at the needles followed by the standard amount of vertical sections. RESULTS: In 28 of the 58 biopsy-proven LM, there was clinical suspicion of LMM, only 3 of these 28 cases were upgraded into LMM. These three cases showed LMM in other sections, whereas only 1 case showed LMM around the needle. Within the group without clinical suspicion of LMM, 2 cases were LMM. Biopsy-proven LM were in fact LMM in 8.6% of the cases and were found without the clinical guidance of the dermatologist. CONCLUSIONS: 8.6% of the biopsy-proven LM were LMM after complete histological examination. In this study, the dermatologist was not able to increase the detection rate of LMM by using clinical and dermoscopic mapping.

Complex melanoma of the scalp: Diagnosis and management aided by confocal microscopy.

Melanomas of lentigo maligna subtype are a steadily growing problem and frequently represent a clinical challenge. A case is reported of a complex melanoma of the scalp illustrating the critical role of confocal microscopy for optimal diagnosis and management.

Clinical features associated with the invasive component in lentigo maligna of the head and neck: A retrospective study of 175 cases.

BACKGROUND: Lentigo maligna (LM) can develop into lentigo maligna melanoma (LMM) with risk of metastatic dissemination. LMM may be underestimated on the basis of the initial biopsy. The invasion may affect both the therapeutic options and the prognosis. OBJECTIVES: To identify the clinical features associated with invasive forms of LM and factors associated with its recurrence. METHODS: A retrospective, single-centre study of consecutive LM and LMM histologically confirmed and treated by surgery between 2009 and 2014. RESULTS: In total, 175 patients with LM/LMM were surgically treated in our establishment. In men, lesions were more likely to be in the "peripheral zone" (41.8%), while in women they were seen more often in the "central zone" (P=0.001). In multivariate analysis, only the peripheral zone was found to be associated with a risk of invasion (P=0.008). The rate of recurrence was 9% and lesions were more likely to be primary LMM (P=0.0006) excised with clear margins. CONCLUSION: The treatment of choice in LM with non-clear margins must be re-excision, especially for lesions situated in the peripheral zone. Close follow-up is recommended due to risk of recurrence, even in the case of clear margins.

Series of Fourteen Cases of Topical Imiquimod 5% in Lentigo Maligna: Treatment Modalities and Clues for Detecting Recurrences.

Topical imiquimod has been used off-label as monotherapy or adjuvant treatment for lentigo maligna. Our aim is to describe treatment modalities, clinical outcomes, and management of recurrence in patients receiving imiquimod for lentigo maligna. Patients from our unit with lentigo maligna or lentigo maligna melanoma treated with imiquimod 5% as monotherapy or in combination with surgery were included in this study. Fourteen cases were recruited (85.7% lentigo maligna and 14.3% lentigo maligna melanoma). Eight patients (57.1%) received imiquimod without surgery, and six (42.9%) underwent narrow excision before beginning treatment. During the follow-up period, pigmentation reappeared in 6 patients (4 postinflammatory hyperpigmentation and 2 relapses). Relapses were managed with very narrow excision (1mm margin) and retreatment with imiquimod 5%. All imiquimod modalities showed well-tolerated side effects and low recurrence rates, with long periods of follow-up. Imiquimod appears to be a versatile option for treating LM in suitable candidates.

Series of Fourteen Cases of Topical Imiquimod 5% in Lentigo Maligna: Treatment Modalities and Clues for Detecting Recurrences. / [Artículo traducido] Serie de 14 casos de tratamiento con imiquimod tópico al 5% en lentigo maligno: modalidades terapéuticas y claves para detectar recidivas.

Topical imiquimod has been used off-label as monotherapy or adjuvant treatment for lentigo maligna. Our aim is to describe treatment modalities, clinical outcomes, and management of recurrence in patients receiving imiquimod for lentigo maligna. Patients from our unit with lentigo maligna or lentigo maligna melanoma treated with imiquimod 5% as monotherapy or in combination with surgery were included in this study. Fourteen cases were recruited (85.7% lentigo maligna and 14.3% lentigo maligna melanoma). Eight patients (57.1%) received imiquimod without surgery, and six (42.9%) underwent narrow excision before beginning treatment. During the follow-up period, pigmentation reappeared in 6 patients (4 postinflammatory hyperpigmentation and 2 relapses). Relapses were managed with very narrow excision (1 mm margin) and retreatment with imiquimod 5%. All imiquimod modalities showed well-tolerated side effects and low recurrence rates, with long periods of follow-up. Imiquimod appears to be a versatile option for treating LM in suitable candidates.