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.     

Utilidad clínica de la microscopia confocal de reflectancia en el manejo del lentigo maligno melanoma

Facial lentigo maligna melanoma can be a diagnostic challenge in daily clinical practice as it has similar clinical and morphological features to other lesions such as solar lentigines and pigmented actinic keratoses. Confocal microscopy is a noninvasive technique that provides real-time images of the epidermis and superficial dermis with cellular-level resolution. We describe 3 cases of suspected facial lentigo maligna that were assessed using dermoscopy and confocal microscopy before histopathology study. In the first case, diagnosed as lentigo maligna melanoma, presurgical mapping by confocal microscopy was performed to define the margins more accurately. In the second and third cases, with a clinical and dermoscopic suspicion of lentigo maligna melanoma, confocal microscopy was used to identify the optimal site for biopsy.     

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 (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.     

[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.     

Cryotherapy for lentigo maligna — is clinical acumen combined with a single punch biopsy good enough for staging?

Aim We aimed to clarity the effectivenes of our staging of LM over a I-year period. Background Cryosurgery has become accepted as a simple and effective treatment for lentigo maligna (LM) but not necessarily lentigo maligna melanoma (LMM). Pigmented epithelial cells are extremely sensitive to cold injury. If adequate freezing is delivered to the proper depth into the dermal appendages, LM should be eradicated. However, if the initial staging does not detect invasion the lesion may be inadequately treated. Methods Over 1 year prospectively. all patients presenting with LM(n= 12) wore stayed clinically by experienced dermatologists and by a single punch biopsy. This was then checked by complete excision of the lesion. Results In 9 patients the clinical and punch biopsy diagnosis was confirmed after excision. Two melanomas were missed clinically but detected on punch biopsy. In one patient the punch biopsy described a “LM with probable invasion elsewhere in the lesion”. Surgical excision yielded a melanoma, 0.8 mm thick. Clark's level 4. In a second patient, punch biopsy diagnosed superficial spreading melanoma (-SSM) in situ, confirmed on excision. Conclusions We therefore feel that clinical diagnosis combined with a single punch biopsy will diagnose invasion when present. We emphasise that cryotherapy should not be performed without punch biopsy confirmation of the clinical diagnosis.     

Simultaneous occurrence of multiple melanoma in situ on sundamaged skin (lentigo maligna), solar lentigo and labial melanosis: the value of dermoscopy in diagnosis

We report on a patient developing simultaneous occurrence of lentigo maligna lesions, solar lentigines and an extensive melanosis of the oral mucosa. Diagnostically, epiluminescence microscopy had a relevant role in the preoperative assessment and selection of suspicious pigmented lesions, as the lesions histologically labelled as lentigo maligna and solar lentigo were clinically indistinguishable. We review the clinical, dermoscopic and histopathologic differential diagnosis of solar lentigo, malignant lentigo and mucosal melanosis with other melanocytic and keratinocytic lesions and discuss the possible relationship between these entities.     

Epidemiological aspects of melanoma at a university hospital dermatology center over a period of 20 years

BACKGROUND

The incidence of melanoma has been steadily rising in past decades. Although it accounts for only 3% of all skin cancers, it is responsible for 75% of deaths.

OBJECTIVE

to describe the epidemiological aspects of melanoma in a university hospital setting over a period of 20 years.

METHODS

A total of 166 patients were analyzed between January 1990 and January 2010 for clinical and histological variables and correlations between them. A 5% level of significance was adopted.

RESULTS

The majority of patients were Caucasians (74%), females (61%), with a mean age at diagnosis of 55. The predominant histological type was lentigo maligna/lentigo maligna melanoma (35.7%) and the head and neck was the most affected site (30.7%). Among non-Caucasians, the acral region was the most affected. Most tumors were in situ (41.1%). Growth of the lesion was the most frequent complaint (58.1%) and bleeding was most frequently associated with melanomas with a depth > 4mm. There were seven deaths (4.2%), with a high risk among men, non-Caucasians and those under 20 years of age, with a Breslow''s depth > 2mm, with lentiginous acral melanoma and with a history of growth and bleeding.

CONCLUSIONS

Our sample differs from most of the studies in the predominant location (head and neck), histological type (lentigo maligna/ lentigo maligna melanoma) and a major risk of death under the age of 20, which could be with a reflex of regional variation. Broader studies are necessary for validation of the results.     

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

BackgroundLentigo 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.ObjectivesTo identify the clinical features associated with invasive forms of LM and factors associated with its recurrence.MethodsA retrospective, single-centre study of consecutive LM and LMM histologically confirmed and treated by surgery between 2009 and 2014.ResultsIn 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.ConclusionThe 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.     

Unstable solar lentigo: A defined separate entity

An unstable solar lentigo is a solar lentigo with areas of melanocytic hyperplasia not extending past the margin of the lesion. They are discrete, macular, pigmented lesions arising on sun‐damaged skin and a subset of typical solar lentigos. Clinically they differ from usual solar lentigines in often being solitary or larger and darker than adjacent solar lentigines. These lesions are of clinical importance as they can arise in close proximity to lentigo maligna and in a single lesion there can be demonstrated changes of solar lentigo, unstable solar lentigo and lentigo maligna. These observations led us to conjecture that unstable solar lentigos could be a precursor lesion to lentigo maligna. In this article we examine the possibility that lentigo maligna can arise within a solar lentigo through an intermediate lesion, the unstable solar lentigo. We propose that the histopathological recognition of this entity will allow for future research into its behaviour and thus management. We review difficulties in the diagnosis of single cell predominant melanocytic proliferations and the concept of unstable lentigo in view of the literature and clinical experience supporting the proposal of its recognition as a separate entity.     

Local treatment of lentigo maligna with azelaic acid

Summary Nazzaro-Porro et al. [5, 6] reported on successful efforts in local treatment of lentigo maligna with azelaic acid (C-9-dicarboxylic acid). Encouraged by their results we similarly treated some lesions of lentigo maligna in a patient suffering from xeroderma pigmentosum with an ointment containing azelaic acid.The obtained results were not convincing in clinical aspects. Histological and electron-microscopic investigations of treated skin specimen yielded cell and tissue structure alterations partly similar to those found by Nazzaro-Porro et al. [6].Compared with the well established surgical and X-ray intervention the described local treatment is in our opinion of less importance.     

Mohs surgery for melanoma in situ

Mohs micrographic surgery is a valuable option for the treatment of melanoma in situ, especially lesions of the lentigo maligna subtype that are clinically ill defined. Complete peripheral margin assessment of a tumor's borders by means of frozen or permanent sections can help reduce the surgical defect size and maximize cure rate as compared with standard excision with preset 5-mm margins. This article reviews the different variations of Mohs micrographic surgery that are currently used for melanoma in situ.     

Amelanotic lentigo maligna melanoma: a unique case and review of the literature

It has been estimated that 2 percent of all melanomas are clinically amelanotic, with amelanotic lentigo maligna melanoma being an even rarer presentation. These neoplasms have presented clinically as neurodermatitis, eczema, and erythema. Given the lack of clinical markers and subsequent delay in diagnosis of these lesions, they are potentially more dangerous than pigmented lentigo maligna melanomas. We report a case of an amelanotic lentigo maligna melanoma presenting as an ill-defined edematous area on the left cheek of an elderly woman.     

Altersmelanome (LM, LMM) an beiden Wangen Analyse der unterschiedlichen Wachstumsdynamik anhand photokatamnestischer Befunde

The dynamics of tumor growth of malignant melanoma may be reconstructed by evaluation of suitable private photographs of the patient. Photohistorical investigations can greatly aid in following the course of development of malignant melanomas and show impressively the slow and protracted growth of initial melanomas. We report on a 90-year-old patient with an in situ melanoma (lentigo maligna) and an invasive lentigo maligna melanoma in the facial region. We were able to obtain complete series of photographs from this patient, which show the different development of the two melanomas over a period of more than 30 years. The first tumor to appear developed very slowly while the later one showed invasive growth after a short time period. Development of multiple primary melanomas is a well recognized phenomenon. The presence of multiple primary melanomas does not appear to be a negative prognostic factor. However, patients with primary melanoma should be made aware of increased risk of development another primary and physicians should do careful total body skin examinations for new primary melanomas as well as for recurrences of the original melanoma.     

Key points in dermoscopic differentiation between lentigo maligna and solar lentigo

A clinical diagnosis of lentigo maligna at an early stage is often difficult even for experienced dermatologists. Differential diagnoses would include solar lentigo, early lesions of seborrheic keratosis, lichen planus-like keratosis, pigmented actinic keratosis and melanocytic nevus. Dermoscopy has been shown to have higher diagnostic accuracy, especially in the diagnosis of pigmented skin lesions, in the past two decades. To aim of the present study was to review the diagnostic key points on dermoscopy in the published work to differentiate lentigo maligna from other differential diagnoses and reassess these important features on dermoscopy for specificity by describing the findings in detail. Diagnostic key points for lentigo maligna/lentigo maligna melanoma on dermoscopy are asymmetrical pigmented follicular openings, rhomboidal structures, annular-granular structures and gray pseudo-network. Lentigo maligna, at first, seems to occur as asymmetrical pigmented follicular openings and/or annular-granular structures, then expand and develop into the rhomboidal structures. Annular-granular structures and gray pseudo-network seem to be observed also in regressive areas of solar lentigo/initial seborrheic keratosis, lichen planus-like keratosis and pigmented actinic keratosis. The four important criteria on dermoscopy for the diagnosis of lentigo maligna have been reviewed, and the former two criteria seem to be more specific, but it might be difficult to recognize these findings without misinterpretation. The latter two seem to be not so specific as they would also be demonstrated in other pigmented epidermal lesions, although the distribution of the structures in these disorders would be inclined to be more homogeneous than that of lentigo maligna.     

Dubreuilh melanoma: and epidemiologic and prognostic study

BACKGROUND: Lentigo maligna melanoma is a specific histoclinical type of melanoma. We studied the epidemiologic features of lentigo maligna melanoma (Dubreuilh's melanoma) and compared prognosis with other types of melanoma. PATIENTS AND METHODS: A retrospective review of 516 cases of cutaneous melanomas, seen from 1985 to 1997, identified 29 cases of lentigo maligna melanoma. Epidemiologic, clinical and prognostic data were collected using a common scoring system for all patients. The chi-squared test, univariate log rank analysis, Cox multiple regression model for multivariate analysis, and actuarial survival curves were applied. RESULTS: The 29 cases of lentigo maligna melanoma (16 women, 13 men) accounted for 5.9 p. 100 of all melanomas. Mean age at diagnosis was 73 years compared with 54 years for others melanomas. Predominant localization was head and neck. There was no prior history of nevi compared with 50 p. 100. Mean delay to diagnosis was 4 years versus 1 year. All patients have had an occupation with to sun exposure. Mean tumoral thickness was 2 mm. Survival was the same as for extensive superficial melanomas and better than for nodular melanomas. Multivariate analysis showed that prognosis was not better in case of lentigo maligna melanoma. Tumoral thickness was the main prognosis factor. DISCUSSION: Our findings confirmed the specific nature of lentigo maligna melanoma and suggested that sun exposure plays an important role. Multivariate analysis did not show that prognosis was any better in case of lentigo maligna melanoma than in other types of melanoma. The thickness of the tumor must be taken into account as for other melanomas.     

Atypical lentiginous junctional naevi of the elderly and melanoma

The diagnosis of atypical lentiginous melanocytic naevi in chronic sun-damaged skin is a clinical and pathological challenge. Mottled skin in the elderly is a result of extensive freckling, guttate hypomelanosis, solar lentigines, seborrhoeic keratoses and small dark lentigines. In addition, atypical lentiginous junctional naevi may be seen as isolated lesions and may merge with lesions that are indistinguishable from lentigo maligna. The predominant site distribution of such lesions on the trunk and limbs and the presence of a nested naevoid pattern on biopsy differs from classical lentigo maligna, which develops mainly on the head and neck. Based on case studies combining dermatoscopy with clinical and pathological features, we have found that atypical lentiginous junctional naevi of the elderly may evolve to lentigo maligna and in some cases to small cell (naevoid) melanomas. Such lesions have been previously classified as dysplastic naevi, atypical melanocytic hyperplasia, atypical melanocytic proliferation, atypical lentiginous melanocytic proliferation or premalignant melanosis (McGovern). The current definition of lentigo maligna appears too narrow and the pathway to lentigo maligna in the elderly skin may include a naevoid subset.     

Amelanotic lentigo maligna and amelanotic lentigo maligna melanoma: a report of three cases mimicking intraepidermal squamous carcinoma

The clinical diagnosis of amelanotic melanoma may pose diagnostic difficulties. We report three cases of amelanotic lentigo maligna, two of which developed an invasive component (lentigo maligna melanoma). The clinical appearances in each case mimicked intraepidermal squamous carcinoma.     

Pagetoid malignant melanoma and lentigo maligna melanoma of toe

Summary Two cases of malignant melanoma on the toe of middle-aged women were examined chiefly by the fluorescence method of Falck and Hillarp. In one of the patients, histopathology of the pigmented tumor on the left middle toe was a Pagetoid (superficial spreading) melanoma in situ, and the subungual granulomatous lesion on the right great toe in the other patient was a lentigo maligna melanoma. On fluorescence microscopy, characteristic findings of the pigment cells lying in the epidermis of both types may be summarized as follows: In the Pagetoid melanoma, the melanoma cells are ovoid, lack dendritic processes, and emit specific yellow fluorescence. In the lentigo maligna melanoma, the pigment cells clearly show dendritic processes, and emit specific green fluorescence.     

Lentigo maligno

Lentigo maligna is a type of in situ melanoma. It develops mainly in middle-aged and elderly individuals on areas of the skin chronically exposed to sunlight. It progresses to its invasive form, lentigo maligna melanoma, in 5% to 50% of cases. Management of lentigo maligna is open to debate, with a notable lack of randomized trials and specific guidelines and protocols. Early diagnosis and treatment is necessary to achieve cure if possible and prevent progression to invasive melanoma with the corresponding risk of metastasis. The treatment of choice for lentigo maligna is surgery. When surgery is not possible, other alternatives are available although outcomes and rates of recurrence are variable. The objective of this study was to review the diagnostic methods and criteria for lentigo maligna, as well as the different surgical options and alternatives to surgery, in order to provide information on the best approach in each case.