Lentigo maligna melanoma has no better prognosis than other types of melanoma

Melanocyte Density in the Diagnosis of Melanoma In Situ in Sun-Damaged Skin

ABSTRACT

Histologic differentiation between melanoma in situ in chronically sun-damaged skin (CSDS) [lentigo maligna (LM)] and CSDS without malignancy is difficult because signs of melanocyte activation and proliferation are found in both. A potentially reliable and quantifiable criterion is melanocyte density (MD). Here, we evaluated whether and to what extent MD allows the distinction between LM and CSDS, which is particularly relevant for the evaluation of borderline cases and surgical margins.Articles assessing MD in LM and/or CSDS were evaluated in a systematic review. The results were categorized and compared according to staining. Cutoff values were included whenever stated.Twenty articles matched the selection criteria. Six hundred forty-four samples of CSDS and 227 samples of LM were considered. In each individual study, mean MD scores were higher for LM than for CSDS. However, looking at the overall study situation, it becomes clear that the data are very heterogeneous and show overlaps. Therefore, no reliable orientation value can be derived. Only 1 article defined a cutoff value.The data of MD in LM in contrast to CSDS were sparse, and a defined cutoff value was only mentioned in 1 article for microphthalmia-associated transcription factor, which cannot yet be generalized. Especially regarding the importance for the definition of surgical resection margins, this unsatisfactory data set highlights the need for further studies. More precise diagnostic criteria could spare some patients extensive and possibly disfiguring surgery.

Skin Cancer Precursors: From Cancer Genomics to Early Diagnosis

Skin cancers, including melanoma and keratinocyte carcinomas, are responsible for increasing health care burden internationally. Risk stratification and early detection are paramount for prevention and less risky treatment to overall improve patient outcomes and disease morbidity. Here, the authors discuss the key concepts leading to skin cancer initiation and progression. The authors also outline precursor and progression models for melanoma and keratinocyte carcinomas, including discussion of genetic alterations associated with the various stages of progression. Finally, the authors discuss the significance of immunoediting and the drivers behind increased risk of cutaneous malignancy in the state of immune dysregulation.

Double Immunohistochemical Labelling of PRAME and Melan A in Slow Mohs Biopsy Margin Assessment of Lentigo Maligna and Lentigo Maligna Melanoma

Introduction: Lentigo maligna (LM) and lentigo maligna melanoma (LMM) predominantly affect the head and neck areas in elderly patients, presenting as challenging ill-defined pigmented lesions with indistinct borders. Surgical margin determination for complete removal remains intricate due to these characteristics. Morphological examination of surgical margins is the key form of determining successful treatment in LM/LMM and underpin the greater margin control provided through the Slow Mohs micrographic surgery (SMMS) approach. Recent assessments have explored the use of immunohistochemistry (IHC) markers, such as Preferentially Expressed Antigen in Melanoma (PRAME), to aid in LM/LMM and margin evaluation, leveraging the selectivity of PRAME labelling in malignant melanocytic neoplasms. Methods: A Novel double-labelling (DL) method incorporating both PRAME and MelanA IHC was employed to further maximise the clinical applicability of PRAME in the assessment of LM/LMM in SMMS biopsies. The evaluation involved 51 samples, comparing the results of the novel DL with respective single-labelling (SL) IHC slides. Results: The findings demonstrated a significant agreement of 96.1% between the DL method and SL slides across the tested samples. The benchmark PRAME SL exhibited a sensitivity of 91.3% in the SMMS specimens and 67.9% in histologically confirmed positive margins. Discussion: This study highlights the utility of PRAME IHC and by extension PRAME DL as an adjunctive tool in the assessment of melanocytic tumours within staged excision margins in SMMS samples.

A cohort analysis of surgically treated primary head and neck lentigo maligna (melanoma): Prognostic value of melanoma subtype and new insights in the clinical value of guideline adherence

BACKGROUND

Knowledge about lentigo maligna (melanoma) (LM/LMM) and its associated prognostic clinicopathological characteristics are limited compared to that of non-LM/LMM subtypes. The current study aimed to determine the clinical relevance of the LM/LMM subtype and its influence on recurrence and survival outcomes.

METHODS

All consecutive cases of primary cutaneous head and neck LM/LMM treated by wide local excision over a ten-year period were retrospectively reviewed and compared to non-LM/LMM. Clinical outcome and prognostic factors were assessed by cumulative incidence and competing risk analyses.

RESULTS

A total of 345 patients were identified. Specific clinicopathological characteristics such as lower median Breslow thickness (1.6 mm versus 2.1 mm; P = 0.013), association with diagnostic sampling errors (17.3% versus 5.2%; P = 0.01), and increased risk of local recurrences due to incomplete resection (18.7% versus 2.3%; P < 0.001), were significantly associated with LM/LMM. Guideline adherence was similar between the two study groups. The positive nodal status at baseline for LMM was low compared to non-LM/LMM (4.2% vs 17.9%; P = 0.037). The LMM subtype, facial localization, and reduced surgical margins (i.e., guideline non-adherence) were not shown to be independent prognostic factors for disease-free, melanoma-specific, or overall survival after correction for competing risks such as patient age and Breslow thickness.

CONCLUSIONS

The LMM subtype was not shown to be prognostically different from non-LM/LMM when corrected for other variables of influence such as patient age and Breslow thickness. Reduced resection margins did not seem to affect disease-free, and melanoma-specific survival and warrant LM/LMM-specific guidelines. Further research is needed to evaluate the value of SLNB in LMM patients.

Clinical size is a poor predictor of invasion in melanoma of the lentigo maligna type

BACKGROUND

There are no well-defined clinical factors to predict the risk of occult invasion in melanoma of the lentigo maligna type (LM) before complete histopathologic analysis.

OBJECTIVE

To evaluate whether clinical size was a predictor of invasion in LM and subclinical extension.

METHODS

Consecutive cases of LM were recorded in a prospectively maintained database from 2006 to 2019. Patient and tumor data were recorded during initial evaluation. The LM clinical area was calculated in square millimeters (length × width). All patients were treated with staged excision.

RESULTS

We included 600 patients. The mean age was 65.9 years (standard deviation, 12.3; range, 27-95 years); 62.8% (n = 377) were men. The mean LM clinical area was 128.32 mm² for in situ lesions versus 200.14 mm for invasive lesions (P = .1). Based on quantile regression, the median margin required for complete removal increased with LM clinical area.

LIMITATIONS

The study was performed in a tertiary cancer center with possible referral bias and more complex cases.

CONCLUSIONS

LM can present with variable clinical size, which may correlate with subclinical extension; however, the presence of invasion is not well estimated by LM clinical area.

Clinical outcomes following surgical treatment of lentigo maligna of the head and neck

INTRODUCTION

Lentigo maligna (LM), a subtype of melanoma in-situ commonly occurring in the head and neck region, often presents a treatment challenge due to anatomical constraints, particularly on the face of mostly elderly patients. This study sought to assess the clinical outcomes of wide local excision of head and neck LM, identify predictors of recurrence and define optimal excision margins.

MATERIALS AND METHODS

Patients with LM treated between January 1997 and December 2012 were identified from the large institutional database of a tertiary center and their data were analyzed.

RESULTS

In 379 patients, 382 lesions were eligible for analysis. Median maximal lesion diameter was 10.5 mm. The mean surgical excision and histopathological clearance margins were 6.2 mm and 4.0 mm, respectively. Median follow-up was 32 months. The LM recurrence rate was 9.9%, and subsequent invasive melanoma developed in 2.3% of cases (mean Breslow thickness 0.7 mm). The recurrence rate was 27.2% if the histological margin was <3.0 mm (median time to recurrence 46.5 months) compared with 2.6% if the margin was ≥3.0 mm. The mean surgical margin required to achieve a histological clearance of ≥3.0 mm was 6.5 mm.

CONCLUSIONS

Our data suggest that to minimize recurrence, a histological margin of ≥3.0 mm is required. To achieve this, a surgical margin of ≥6.5 mm was required. This is greater than the 5 mm margin recommended in some national guidelines. Careful long-term follow-up is required for all patients because of the risk of recurrence.

The Emperor's New Clothes: A Critique of the Current WHO Classification of Malignant Melanoma

The World Health Organization's classification of skin tumors of 2018 presents melanoma as a loose assembly of independent biologic entities, each of which is characterized by a distinctive constellation of clinical, histopathologic, and molecular findings that evolve through different pathways of lesional progression from a benign to an intermediate and, ultimately, malignant tumor. The alleged pathways, however, are based on vague correlations and fail to take into account the common occurrence of lesions that cannot be assigned to either of them. Moreover, there is no such thing as a lesional progression. The evolvement of neoplasms is always a clonal and, therefore, initially focal event. In the majority of melanomas, there is no evidence of a juxtaposition of a benign, intermediate, and malignant portion. Occasionally, a melanoma may develop within the confines of a melanocytic nevus, but a nevus cannot transform into melanoma. The concept of lesional progression merely serves to handle problems of differential diagnosis because it obscures and, in fact, denies the difference between benign and malignant neoplasms. In the current classification of the World Health Organization, every lesion is said to bear some risk of malignant progression, intermediate categories are recognized for all alleged pathways, and no distinction is made between "high-grade dysplasia" and melanoma in situ. Differentiation between benign and malignant neoplasms of melanocytes may be difficult, but the concept of lesional progression does not address those problems; it merely offers evasions under the disguise of diagnoses.

Measuring the horizontal and vertical growth rates of superficial spreading melanoma: a pilot study with sequential digital dermoscopy

BACKGROUND

Some authors have hypothesized that the initial kinetics of the primary melanoma (MM) growth could reflect its biologic aggressiveness. The aim of this study was to pilot a measure of the horizontal vs. vertical growth of superficial spreading melanomas (SSM).

METHODS

The dermoscopic images of twenty-three consecutive MMs (17 SSMs and 6 MMs in situ), excised after digital sequential dermoscopy, were reviewed. We built up two indexes: 1) dROG (digital Rate of Growth) defined as Breslow thickness/(t1-tR), where t1 was the reported time of the first dermoscopic image acquisition and tR was the reported time of the acquisition before the lesion excision; 2) lHGR (linear Horizontal Growth Rate) took into account the greater axis of the lesion at two time points, at the time (t1) of the first image acquisition (D1) and before (tR) lesion excision (DR). The index was computed as (DR-D1)/(t1-tR). We built up the Composite Rate of Growth index (cROG) calculated as dROG/lHRG. If the value of cROG is <1 the superficial growth is prevalent on the vertical growth, and if the value is >1 the vertical growth is prevalent on the superficial growth.

RESULTS

In 82.6% of lesions the horizontal growth was prevalent on the vertical growth, and in 17.4% of cases the vertical growth was equal or prevalent on the superficial growth.

CONCLUSIONS

A small proportion of SSMs with a slow horizontal growth could have a precocious vertical growth. Other larger studies are needed to confirm this observation.

Tumor genetic heterogeneity analysis of chronic sun-damaged melanoma

Chronic sun‐damaged (CSD) melanoma represents 10%–20% of cutaneous melanomas and is characterized by infrequent BRAF V600E mutations and high mutational load. However, the order of genetic events or the extent of intra‐tumor heterogeneity (ITH) in CSD^high melanoma is still unknown. Ultra‐deep targeted sequencing of 40 cancer‐associated genes was performed in 72 in situ or invasive CMM, including 23 CSD^high cases. In addition, we performed whole exome and RNA sequencing on multiple regions of primary tumor and multiple in‐transit metastases from one CSD^high melanoma patient. We found no significant difference in mutation frequency in melanoma‐related genes or in mutational load between in situ and invasive CSD^high lesions, while this difference was observed in CSD^low lesions. In addition, increased frequency of BRAF V600K, NF1, and TP53 mutations (p < .01, Fisher's exact test) was found in CSD^high melanomas. Sequencing of multiple specimens from one CSD^high patient revealed strikingly limited ITH with >95% shared mutations. Our results provide evidence that CSD^high and CSD^low melanomas are distinct molecular entities that progress via different genetic routes.

Upstaging From Melanoma in Situ to Invasive Melanoma on the Head and Neck After Complete Surgical Resection

BACKGROUND

Melanoma in situ (MIS) diagnosed from a subtotal biopsy may be upstaged to invasive melanoma after resection. The frequency of this phenomenon is markedly variable.

OBJECTIVE

To quantify the rate of upstaging MIS on the head and neck after resection at this institution, characterize the location of the invasive component relative to the clinically evident lesion, and determine the rate of upstaging with time.

MATERIALS AND METHODS

The authors retrospectively reviewed clinical records of adult patients with a preoperative diagnosis of MIS on the head and neck from January 1994 to August 2012. Patient and tumor characteristics were recorded.

RESULTS

In total, 624 patients met the inclusion criteria and 24 (4%) were upstaged after resection. Four patients had invasive disease beyond the clinically evident lesion. The annual percentage of upstaged lesions seemed to show an increasing trend with time.

CONCLUSION

Upstaging of MIS on the head and neck occurs at a relatively low rate that may be increasing with time. Invasive components of lentigo maligna melanoma may exist beyond the clinically evident margins. Histological examination of the maximal amount of the surgical specimen is paramount for optimal staging and treatment of MIS.

Diagnosis and management of lentigo maligna: a review

Lentigo maligna is a melanocytic neoplasm occurring on sun-exposed skin, usually on the head and neck, of middle-aged and elderly patients. It is thought to represent the in situ phase of lentigo maligna melanoma. The ill-defined nature and potentially large size of lesions can pose significant diagnostic and treatment challenges. The goal of therapy is to cure the lesions in order to prevent development of invasive disease, and surgical excision is the treatment of choice to achieve clear histological margins. Nonsurgical treatment modalities have been reported; however, evidence is lacking to support their use. Age, general health, and comorbidities need to be taken into account when deciding the right treatment modality for each individual patient.

Cutaneous Melanomas of the Eyelid

Cutaneous eyelid melanomas are very rare lesions. The lentiginous subtypes are the most frequent melanocytic lesions of the eyelid and can be likened to conjunctival melanocytic lesions like PAM, PAM with atypia and conjunctival melanoma. Compared to melanomas elsewhere on the body, eyelid melanomas have special considerations. Eyelid skin is very thin, the mucocutaneous junction at the lid margin can affect prognosis, the lymphatic drainage pattern is very variable and there is an inherent difficulty to excise wide margins without sacrificing important structures. A customized excision approach, using tissue-sparing "Slow-Mohs" technique, is suggested. Sentinel lymph node dissection has an evolving therapeutic role but remains controversial.

Lentigo maligna

Lentigo maligna (LM), a melanoma in situ, is a fairly common melanocytic lesion that usually develops on the chronically sun-exposed skin of the head and neck of Caucasians. It occurs mostly in people older than 40 years, with an incidence rate that increases with age and peaks in the seventh and eighth decades of life. Its diagnosis and treatment remain challenging. In this article, we review the history, epidemiology, clinical presentation, histology, and treatment of LM.

Cutaneous lesions of the external ear

Skin diseases on the external aspect of the ear are seen in a variety of medical disciplines. Dermatologists, othorhinolaryngologists, general practitioners, general and plastic surgeons are regularly consulted regarding cutaneous lesions on the ear.

This article will focus on those diseases wherefore surgery or laser therapy is considered as a possible treatment option or which are potentially subject to surgical evaluation.

Cryosurgical treatment of lentigo maligna

BACKGROUND

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Malignant melanoma in the 21st century, part 1: epidemiology, risk factors, screening, prevention, and diagnosis

Malignant melanoma is an aggressive, therapy-resistant malignancy of melanocytes. The incidence of melanoma has been steadily increasing worldwide, resulting in an increasing public health problem. Exposure to solar UV radiation, fair skin, dysplastic nevi syndrome, and a family history of melanoma are major risk factors for melanoma development. The interactions between genetic and environmental risk factors that promote melanomagenesis are currently the subject of ongoing research. Avoidance of UV radiation and surveillance of high-risk patients have the potential to reduce the population burden of melanoma. Biopsies of the primary tumor and sampling of draining lymph nodes are required for optimal diagnosis and staging. Several clinically relevant pathologic subtypes have been identified and need to be recognized. Therapy for early disease is predominantly surgical, with a minor benefit noted with the use of adjuvant therapy. Management of systemic melanoma is a challenge because of a paucity of active treatment modalities. In the first part of this 2-part review, we discuss epidemiology, risk factors, screening, prevention, and diagnosis of malignant melanoma. Part 2 (which will appear in the April 2007 issue) will review melanoma staging, prognosis, and treatment.

Mohs micrographic surgery in the treatment of lentigo maligna and melanoma

BACKGROUND AND OBJECTIVES

The treatment of lentigo maligna (LM) and lentigo maligna melanoma (LMM) is challenging due to lesion location, size, patient age, and potential for recurrence and spread. The largest studies to date confirm that for melanocytic tumours, MMS provides high local control rates while minimizing tissue loss. Herein we report our local control rate for melanoma treated by MMS over a decade.

METHODS

Charts were reviewed on all patients with melanocytic tumors treated by a single physician (JPA) using MMS over the time period of 1993-2002. Demographic, surgical and pathological details were recorded. Patients were followed for local, regional and distant recurrences.

RESULTS

The patient population was comprised of 199 patients with 202 melanomas. There were 69 invasive lesions, with a mean Breslow depth of 0.92 mm (0.2-3.6 mm). The mean number of levels required to clear the lesions was 2.7 (1-7), resulting in a mean defect size of 11.8 cm2 (0.9-70.7 cm2). Patients with LMM were significantly older (73.2 vs. 66.5 yrs, p = 0.012) and had larger defects after MMS (16.74 cm2 vs. 10.27 cm2) than patients with LM. At a mean follow-up of 29.8 months, there were no local recurrences, four regional recurrences, and two distant recurrences.

CONCLUSION

MMS is an effective modality for the clearance of melanocytic tumors.

Prognosticators of melanoma, the melanoma report, and the sentinel lymph node

Since the 1960s, the clinical characteristics of melanoma, its histopathology and its biological basis have been the subject of intense study at pigmented lesion clinics in North America, Europe, and Australia. More recently, the immense database of the Melanoma Committee of the American Joint Committee on Cancer (AJCC) has been exploited through complex mathematical models to measure the impact of various histologic features of primary melanomas and of sentinel lymph node deposits and to correlate these parameters with patient survival. The wealth of modern information available to pathologists and clinicians has become of vital interest to the prognostication of the individual patient with melanoma. The purpose of this review is to bring to the attention of anatomic pathologists the essential characteristics of the pathology report for primary cutaneous melanoma in the modern era.

Increasing incidence of lentigo maligna melanoma subtypes: northern California and national trends 1990-2000

Worldwide, lentigo maligna melanoma (LMM) comprises 4%-15% of cutaneous melanoma and occurs less commonly than superficial spreading or nodular subtypes. We assessed the incidence of melanoma subtypes in regional and national Surveillance, Epidemiology, and End Results (SEER) cancer registry data from 1990 to 2000. Because 30%-50% of SEER data were not classified by histogenetic type, we compared the observed SEER trends with an age-matched population of 1024 cases from Stanford University Medical Center (SUMC) (1995-2000). SEER data revealed lentigo maligna (LM) as the most prevalent in situ subtype (79%-83%), and that LMM has been increasing at a higher rate compared with other subtypes and to all invasive melanoma combined for patients aged 45-64 and > or =65 y. The SUMC data demonstrated LM and LMM as the only subtypes increasing in incidence over the study period. In both groups, LM comprised > or =75% of in situ melanoma and LMM > or =27% of invasive melanoma in men 65 y and older. Regional and national SEER data suggest an increasing incidence of LM and LMM, particularly in men > or =age 65. An increased incidence of LM subtypes should direct melanoma screening to heavily sun-exposed sites, where these subtypes predominate.

Histologic similarities between lentigo maligna and dysplastic nevus: importance of clinicopathologic distinction

BACKGROUND

Lentigo maligna (LM) can histologically simulate dysplastic nevus (DN). Partial biopsy of LM may lead to misdiagnosis.

METHODS

One hundred and fourteen cases of LM and LM melanoma (LMM) were diagnosed at the Veterans Affairs Palo Alto Health Care System (1993-2002). Biopsy and excision specimens for 68 in situ and 28 invasive melanomas were classified as having predominant classical LM features, predominant DN-like morphology, or a mixed pattern.

RESULTS

Biopsy specimens demonstrated a predominant classical pattern in 38% (25/65) LM and 36% (10/28) LMM, predominant DN-like features in 43% (28/65) LM and 25% (7/28) LMM, and mixed pattern in 15% (10/65) LM and 29% (8/28) LMM. Most LM and LMM biopsies were partial. Significant DN-like features were present in 51% LM and 57% LMM excision specimens. Median age was 72 years for LM and 73 years for LMM, mean lesion diameters were 1.3 and 1.7 cm for LM and LMM, respectively, and 85% of LM and 75% of LMM cases were located on heavily sun-exposed sites.

CONCLUSIONS

Misdiagnosis of LM or LMM as DN could have devastating results. Large pigmented lesions on sun-damaged skin in elderly individuals should warrant consideration of LM/LMM diagnosis, even in the setting of DN-like features histologically. Excisional biopsy may help to avoid misdiagnosis.

Follicular malignant melanoma: a variant of melanoma to be distinguished from lentigo maligna melanoma

Follicular malignant melanoma can be regarded as a rare and unique presentation of melanoma. It is characterized by a deep-seated follicular structure in which atypical melanocytes extend downward along the follicular epithelium and permeate parts of the follicle as well as the adjacent dermis. The clinical diagnosis of follicular malignant melanoma may be difficult because the tumor mostly resembles a comedo or a pigmented cyst. We studied five cases of follicular malignant melanoma in which the patients were between 61 and 82 years old. Three lesions were localized on the nose, one on the cheek, and one on the back of the neck. Clinically, all five cases measured distinctly less than 0.5 cm in size. While lentigo maligna is traditionally known as a pigmented macule in actinically damaged skin that gradually evolves in a slow process before invasive growth, three follicular malignant melanomas had developed in relatively short timeframes of 9 months to 1 1/2 years. In all five cases the inconspicuous clinical appearance did not herald a malignant melanoma with invasive growth. Follicular malignant melanoma underlines the importance of a correct excision technique with subsequent histologic workup and diagnosis. Superficial shave excision or even laser treatment in these specific cases may lead to a fatal prognosis for the patient.

The perimeter technique for lentigo maligna: an alternative to Mohs micrographic surgery

BACKGROUND

Lentigo maligna (LM) presents a challenge for complete surgical excision because of its extensive subclinical spread and predilection for the face.

OBJECTIVE

To report our experience using the staged perimeter technique as an alternative to Mohs micrographic surgery for treatment of LM.

METHODS

The perimeter procedure was performed on 11 patients with LM between March 2003 and June 2004. Data on patient and lesion characteristics, number of stages required to obtain clear margins, and follow-up was obtained by chart review.

RESULTS

A mean of 1.9 stages were required to achieve clear margins. A mean of 7 tissue specimens were sent to pathology per patient for evaluation. After a mean follow-up of 4.7 months, all patients were free of recurrence.

CONCLUSIONS

The perimeter technique is a simple method of margin-controlled excision of LM. The main advantage is that all margins are examined with permanent sections. The main drawback is that multiple operative sessions are required to complete the procedure. This technique does not require specific Mohs training and is therefore applicable to non-Mohs surgeons.

Prolonged evolution of a lentigo maligna

Lentigo maligna (LM) is a melanocytic lesion which is a potential precursor to melanoma and often has a prolonged intraepidermal growth phase before evolving into lentigo maligna melanoma (LMM). LM is also noted for its tendency to locally recur after treatment. We present a patient who had a persistent LM on her left cheek which, despite multiple excisions, persisted and transformed into a partially amelanotic LMM roughly three decades later. Our patient's course was also notable for this melanoma recurring at the edge of, and subsequently migrating into, a previously placed skin graft.

Prognostic signs in melanoma: state of the art

Prognoses for melanoma patients are currently based on statistically confirmed parameters, above all the Breslow thickness and number of lymph node and/or distant metastases. However, metastases can develop even with "thin" melanomas (< 0.7 mm), while survival has been recorded in patients with tumours classified as "thick" (> 4 mm). This review of the literature examines the most recent advances in prognostic markers for melanoma (serological, immunohistochemical, histological, genetic and surgical). These markers offer interesting possibilities in terms of diagnostic certainty, identification of early growth phases and estimation of the tumour's potential for progression and metastasis. It is reasonable to assume that their combined use can provide useful information for formulating prognoses that are not only statistically valid but also individualized.

Mapped serial excision for periocular lentigo maligna and lentigo maligna melanoma

PURPOSE

To report the early cure rate for periocular lentigo maligna (LM) and LM melanoma (LMM), using modified Mohs surgery with vertically cut paraffin-embedded sections (mapped serial excision [MSE]). A secondary aim was to identify differences in the clinical features and outcomes between periocular LM and LMM and those found elsewhere on the head and neck.

DESIGN

Prospective, noncomparative, interventional case series.

PARTICIPANTS

One hundred thirty-five patients undergoing 141 MSE procedures.

METHODS

A prospective series of 141 MSE procedures for LM and LMM over a 10-year period (1993-2002) in a single-center Mohs surgical unit.

MAIN OUTCOME MEASURES

Recurrence, site, size of LM or LMM, invasiveness, prior recurrence, clear margin of excision, size of final defect, and number of levels required for complete excision.

RESULTS

One hundred forty-one MSE procedures, of which 23% (32/141) were for LMM and 19% (27/141) were for periocular lesions. Location or prior recurrence were not predictive of invasive disease; however, the size distribution of the initial lesion (P = 0.0354) and the final defect after MSE (P = 0.0183) were larger in LMM. Thirty-one percent of LM and 14% of LMM less than 1 mm thick required larger than 5-mm and 1-cm margins, respectively, for complete excision. Mean follow-up of 32 months (range, 1-100 months) revealed 4 recurrences (3%), of which two were periocular (P = 0.188).

CONCLUSIONS

Our review is the largest prospective series of MSE for LM and LMM and suggests that it is the treatment of choice in these forms of melanoma. Mapped serial excision offers a high early cure rate in conjunction with tissue conservation, which is of particular relevance in the periocular region. There were no significant differences between periocular LM and LMM and those found elsewhere in the head and neck region. It also appears that the current recommendations of 5-mm margins for in situ melanoma (LM) and 1-cm margins for melanoma less than 1 mm thick are insufficient for complete excision of LM or LMM, emphasizing the importance of margin-controlled excision of these lesions.

Local recurrence in melanoma in situ: influence of sex, age, site of involvement and therapeutic modalities

BACKGROUND

Melanoma in situ (MIS) occurs on various body sites, in various age groups, and is managed by a variety of treatment modalities. Despite early treatment, recurrences may be encountered.

OBJECTIVES

To evaluate the influence of sex, age, body site and treatment modalities on recurrence rate in MIS. Methods Histologically confirmed cases of MIS from our dermatopathological database (n = 1351) from 1990 to 2000 were statistically analysed with respect to epidemiological characteristics, treatment modalities and outcome. Treatment modalities of the included MIS were evaluated by searching for data in the medical records and histopathological data sheets.

RESULTS

There was a predominance of female patients (60.8%), and of involvement of the head and neck (53.4%). Total excision was performed in 95.9% of all patients; the remainder received cryotherapy, laser therapy or radiotherapy. In 265 patients, no data on definitive treatment were available. Alternatives to total excision were particularly performed in patients with advanced age and with lesions localized on the face. The mean +/- SD 5-year recurrence rate was 6.8 +/- 1.3% for surgically removed lesions, but was 31.3 +/- 8.5% for lesions treated by other modalities (log rank test: P < 0.0001). In a multivariate approach, mode of therapy and site of involvement, but not age, were significant prognostic variables (Cox proportional hazard model: P < 0.01).

CONCLUSIONS

In MIS, treatment modalities other than surgical excision may be used in certain situations, but carry a significantly increased risk of local recurrence.