Acral (volar-subungual) melanoma in Auckland, New Zealand

Prevalence of subungual melanoma in patients with cutaneous malignant melanoma: A systematic review and meta-analysis

BACKGROUND

Subungual melanoma (SUM) is a rare type of cutaneous malignant melanoma (CMM) associated with poor prognosis, while data regarding its prevalence are scarce.

OBJECTIVES

We sought to provide a comprehensive systematic review and meta-analysis of the prevalence rates of SUM among all types of CMM, considering certain demographic and clinical characteristics.

METHODS

The MEDLINE electronic database was searched systematically to identify eligible studies providing prevalence rate estimates of SUM in patients with CMM. Included studies were further analysed to estimate the relative prevalences of SUM according to study design, study years, geographical region and sex distribution.

RESULTS

Twenty-eight studies met the inclusion criteria. The overall SUM prevalence was 1.9% (95% CI [1.5%-2.3%]). The prevalence of SUM did not differ significantly between population- and hospital-based studies and remained stable over time. However, it was found to be significantly higher in Asians compared to patients of other geographical regions as well as in studies with more men than women compared to those with female preponderance (p < 0.001).

CONCLUSIONS

In all, the overall SUM prevalence among all subtypes of CMM was estimated at 1.9%, without significant changes over time, and was found to exhibit significant variability between subgroups of different geographical regions.

More than just acral melanoma: the controversies of defining the disease

Acral melanoma (AM) is a malignant cutaneous melanocytic tumour specifically located on the palms, soles, and nail apparatus, which are areas of glabrous (hairless) skin. Acral lentiginous melanoma, a subtype of AM, represents a histopathological subtype diagnosis of cutaneous melanoma with unique morphological and structural features. Despite clear definitions, the misuse of these terms and the inconsistency in reporting the histopathological features of AM cases have become a major obstacle to the study of the disease. In this review, we discuss the epidemiology, histopathological features, prognosis, and genetic profile of AM, highlighting the differences observed when histopathological subtypes are considered. The increasing global effort to characterise AM cases from ethnically diverse populations would benefit greatly from a more consistent classification of the disease.

Comparative Analysis of Acral Melanoma in Chinese and Caucasian Patients

Background

Acral melanoma (AM) is a rare subtype of melanoma, which is one of the least common in Caucasian patients but is a common subtype of melanoma in Chinese patients. It is unclear if prognosis differs between Chinese and Caucasian patients diagnosed with AM. The aim of our study is to investigate patient characteristics and survival differences between Chinese and Caucasian AM patients.

Methods

Two large institutional melanoma databases from Fudan University Shanghai Cancer Center (FUSCC) and Mayo Clinic enterprise were retrospectively reviewed from 2009 to 2015. Clinicopathologic and survival data were collected and analyzed between the two groups. The primary outcome was disease-specific survival (DSS) and was calculated using the Kaplan Meier (KM) method.

Results

The Chinese group presented with more advanced disease compared with Caucasians: thicker Breslow depth (median 3.0 mm vs. 1.2 mm, p=0.003), more ulcerated disease (66.1% vs. 29%; p < 0.001), and advanced stages (stage II/III 84.3% vs. 37.1%; p < 0.001). No significant difference was identified in terms of age at diagnosis, location, histologic subtypes, or node positive rate. The 5-year DSS rate was 68.4% and 73% (p=0.56) in Chinese and Caucasians AM patients, respectively. Male gender, Breslow thickness, ulceration, and positive sentinel lymph nodes were independent poor prognostic factors on multivariate analysis.

Conclusions

There appears to be no difference in stage-stratified survival between Chinese and Caucasians, supporting the implementation of clinical trials for AM that could include both Chinese and Caucasian patients.

Acral Lentiginous Melanoma: Incidence and Survival in the United States, 2006-2015, an Analysis of the SEER Registry

BACKGROUND

Acral lentiginous melanoma (ALM) is one of the four major subtypes in cutaneous malignant melanoma (CMM). We aimed to study the incidence and survival of ALM in the United States in recent 10 y and compare the survival between ALM and nonacral CMM. In the meantime, racial disparity and prognostic factors associated with survival were investigated.

METHODS

All the cases of ALM registered in the Surveillance, Epidemiology, and End Results registry from 2006 to 2015 were retrieved, including non-Hispanic whites (NHW), black Americans (blacks), Asian/Pacific Islanders, and Hispanic whites. Age-adjusted incidence was calculated. Clinicopathologic data, including age, gender, race, geographic location, Breslow thickness, ulceration, pathologic staging, sentinel lymph node status, and surgical approach, were collected and analyzed. Melanoma-specific survival (MSS) was analyzed in patients with ALM and CMM. The Kaplan-Meier method was used to estimate the influence of clinicopathologic data on ALM MSS. Only cases with complete staging and active follow-up were included in prognostic factor analysis.

RESULTS

A total of 1724 ALM and 87,442 nonacral CMM patients were included in the study. For ALM patients, the age-adjusted incidence rate was 2.0 per million person-years. The proportion of ALM among all melanoma subtypes was greatest in blacks (32.6%). The 5-y MSS rates of ALM were lower than CMM overall (80.6% versus 93.0%, P < 0.001, respectively). When controlled by stage, the difference was significant in patients diagnosed at stages I and III. ALM 5-y MSS rates were highest (84.3%) in NHW, intermediate in Asian/Pacific Islanders (76.6%), Hispanic white (72.0%), and lowest in blacks (66.9%). Blacks were elderly, male predominant, located in East and Middle American, and had thicker, more ulcerated, advanced disease as compared with NHWs. When controlled by stage, survival difference was significant between NHWs and blacks in stage I (P = 0.004) and stage III (P = 0.005) patients. Gender, race, sentinel lymph node status, and pathologic stage were identified as independent risk factors in multivariate analysis.

CONCLUSIONS

The incidence of ALM has been steady in recent 10 y and more prevalent in aged people. ALM is associated with a worse prognosis than CMM. Black Americans have the worst prognosis, and survival difference is significant between NHW and blacks.

Nail Apparatus Melanoma: Experience of 10 Years in a Single Institution

Background

Nail apparatus melanoma (NAM) is rare. The higher mortality reported in the literature is most likely due to advanced disease associated with delayed diagnosis and treatment.

Objective

All patients diagnosed with NAM were followed at a single reference center during a period of 10 years, with emphasis on dermatological and histological findings. Clinical outcomes were included.

Methods

A retrospective review of medical records, photographs, and histopathological examination.

Results

73.7% of the patients were female and their mean age was 47 years. Caucasian and African-American patients had a similar incidence (47.4%). There was only 1 Asian patient in this study (5.3%). All patients presented with nail plate pigmentation. The mean prediagnosis duration was 33 months. A total of 63.2% patients had in situ melanoma and an average Breslow index of 2.18 mm in invasive cases. Fifteen patients underwent conservative surgery and 3 underwent phalanx amputation. All patients survived, and 4 have had more than a 5-year follow-up.

Conclusion

In situ lesions showed longitudinal bands or total melanonychia with no nail dystrophy. Invasive cases presented with dystrophic lesions (longitudinal splitting of the nail). Conservative surgery provides a good option without worsening the prognosis. All dermatologists should be aware of early signs of NAM, since prognosis depends on early treatment.

Acral Melanoma in Chinese: A Clinicopathological and Prognostic Study of 142 cases

Acral melanoma (AM), as a peculiar subgroup of melanoma, is rare in Caucasians but has higher incidence in Asians. Large series of study on AM with clinicopathological features and prognostic factors is still limited, especially in Asian population. We retrospectively collected clinical, pathological and follow-up data of 142 AM cases. All patients were Chinese, with the age ranging from 24 to 87 years (mean 62.0; median 62.0). The Breslow thickness of primary lesions ranged from 0.6 to 16.3 mm (mean 4.9; median 3.7). 85.9% of the patients had acral lentiginous histologic subtype. Plantar was the most frequently involved site, followed by heels. Statistically, duration of the lesion before diagnosis (≤2.5 years), Breslow thickness >4.0 mm (T4), high mitotic index (>15 mm⁻²), presence of vascular invasion, regional lymph node metastasis at diagnosis and pathologic stage (II/III/IV) were found to be independent prognostic factors in both univariate and multivariate analyses. The prognosis of AM in Chinese is extremely poor. Our 5- and 10-year disease-specific survival (DSS) rates were 53.3% and 27.4%, respectively. Therefore, AM in Asians represents a more biologically aggressive melanoma subtype and is thought to carry a worse prognosis when compared with other races or cutaneous melanomas in other anatomic sites.

Melanoma: Clinical Presentations

The malignant cell in melanoma is the melanocyte. Because melanocytes are located in the basal layer of the epidermis, melanoma is most commonly seen on the skin. However, melanoma can also arise on mucosal surfaces such as the oral cavity, the upper gastrointestinal mucosa, the genital mucosa, as well as the uveal tract of the eye and leptomeninges. Melanomas tend to be pigmented but can also present as pink or red lesions. They can mimic benign or other malignant skin lesions. This chapter presents the spectrum of typical and less typical presentations of melanoma, as well as patterns of spread. It is divided into (1) cutaneous lesions; (2) patterns of regional spread, (3) non-cutaneous lesions; and (4) distant metastases.

Diagnosis using the nail bed and hyponychium

"Nails protect the fingertips and toes. Diseases affecting the nail can cause cosmetic disfigurement and social embarrassment. Physical functioning may be impaired. Disorders of the nail bed may cause pain or create difficulty grasping fine objects. The nail bed is the area beneath the nail plate between the lunula and the hyponychium. Disorders of the nail bed can cause onycholysis, subungual hyperkeratosis, and/or onychogryphosis. Ventral pterygium is less common. Tumors of the nail bed are rare and commonly missed."

Analysis of recurrence patterns in acral versus nonacral melanoma: should histologic subtype influence treatment guidelines?

Current surgical treatment of primary melanoma is uniform for all histosubtypes, although certain types of melanoma, such as acral lentiginous melanoma (ALM), have a worse prognosis. No study has explored the effectiveness of standard melanoma treatment guidelines for managing ALM compared with nonacral melanoma (NAM). Study subjects were identified from a prospectively enrolled database of patients with primary melanoma at New York University. Patients with ALM were matched to those with NAM (1:3) by gender and melanoma stage, including substage (ALM, 61; NAM, 183). All patients received standard-of-care treatment. Recurrence and survival outcomes in both cohorts were compared. ALM histologic subtype was an independent negative predictor of recurrence-free survival (hazard ratio [HR], 2.24; P=.001) and melanoma-specific survival (HR, 2.58; P=.001) compared with NAM. Recurrence was significantly more common in patients with ALM than in those with NAM (49% vs 30%; P=.007). For tumors less than 2 mm in thickness, a significantly higher recurrence rate was seen with ALM versus NAM (P=.048). No significant difference was seen in recurrence for tumors greater than 2 mm (P=.12). Notably, the rate of locoregional recurrence was nearly double for ALM compared with NAM (P=.001). The data presented herein reveal a high rate of locoregional failure in ALM compared with NAM when controlling for AJCC stage. These results raise the question of whether ALM may require more aggressive surgical treatment than nonacral cutaneous melanomas of equal thickness, particularly in tumors less than 2 mm thick. Larger multicenter trials are necessary for further conclusions.

Acral lentiginous melanoma: histopathological prognostic features of 121 cases

BACKGROUND

Acral lentiginous melanoma (ALM) is the fourth histopathological subtype of malignant melanoma, accounting for < 10% of all melanomas in white-skinned populations. It is characterized by a lentiginous pattern of proliferation of the intraepidermal component of the tumour. Its individualization is still controversial, especially in regard of its prognostic value.

OBJECTIVES

To characterize better ALM from a pathological point of view and to assess the prognostic value of all histopathological features of ALM.

METHODS

We performed a review of all cases of ALM followed from 1996 to 2004 at the University Hospital Department of Dermatology, Lyon, France. We examined all haematoxylin, eosin and saffron-stained tissue sections of the primary lesions. Several pathological parameters of interest in melanoma were evaluated for disease-free and specific survival with the Kaplan-Meier method and the Cox proportional hazards regression model.

RESULTS

Representative histological material was available for 121 patients. The mean Breslow thickness was 2.5 mm (in situ-20 mm). Fifteen lesions (12%) were in situ, nine (7%) were at Clark level II, 35 (29%) at III, 40 (33%) IV and 22 (18%) V. Extension along adnexal structures was found in almost half of the ALMs (46%), without prognostic significance. Seventeen (14%) lesions showed no microscopic pigmentation. Remnants of pre-existing naevus were found in four (3%) melanomas. The width of the 36 (30%) ulcerated lesions ranged from 1 to 20 mm (mean 7.6). Ulceration and its width were both associated with a large tumour thickness (P < 0.01), a high level of invasion (P < 0.01), the presence of vascular invasion (P < 0.01) and the lack of pigment production (P < 0.01). Among the 99 ALMs which were in the vertical growth phase (VGP), 21 showed a high mitotic rate (> 6 mitoses mm(-2)). A high mitotic rate was found to be significantly associated with the presence of ulceration (P < 0.01). The presence of microscopic satellites was noted in 10 (10%) lesions. The uncommon presence of small cells (8%) in the VGP was statistically significantly (P < 0.01) associated with a worse prognosis compared with other cell types. Multivariate analysis identified mitotic rate (P < 0.01), microsatellites (P = 0.05), Clark level (P = 0.01) and gender (P = 0.03) as independent prognostic factors for disease-free survival. Only the presence of microsatellites (P = 0.02) and a high mitotic rate (P < 0.01) were independently correlated with specific survival in ALM.

CONCLUSIONS

This is a detailed pathological study of a large cohort with ALM, an uncommon subtype of melanoma. Mitotic activity appears to be of particular importance in predicting the outcome of ALM.

Acral lentiginous melanoma: a clinicoprognostic study of 126 cases

BACKGROUND

Although the histopathological subtype of melanoma has not been clearly proven to carry independent prognostic significance, acral lentiginous melanoma (ALM) seems to confer a poorer prognosis mainly because disease is often more advanced at the time of diagnosis.

OBJECTIVES

To investigate the distinctive epidemiological and clinical characteristics of ALM, a peculiar histological entity, and to identify prognostic factors.

METHODS

We performed a register-based review of cases from a single large referral centre, the University Hospital Department of Dermatology, Lyons, France. We reviewed patient demographics, the initial presentation of the lesion, and clinical outcome. ALM-specific and disease-free survival were estimated using the KaplanMeier method and compared using the log-rank test. A Cox model was used to identify prognostic factors.

RESULTS

One hundred and twenty-six patients were identified as having histopathology-proven ALM in our melanoma patient register from 1996 to 2004. There were 46 (37%) subungual ALM and 80 (63%) ALM on soles, palms and nonvolar sites. The mean age at diagnosis was 63 years. There were 44 (35%) men and 82 (65%) women, sex ratio M/F 1 : 1.86. The mean Breslow thickness was 2.51 mm (range: in situ to 20 mm). There was no evidence of overexposure to ultraviolet radiation, nor was there found a predisposing genetic trait. Only 16 (13%) patients recalled a history of trauma. Thirty-four ALM (28%) were unpigmented. The median ALM-specific and disease-free survival were 13.5 and 10.1 years, respectively. The 5-year survival rate was 76%. Multivariate analysis identified tumour thickness, male gender and amelanosis as independent clinical prognostic factors for both ALM-specific and disease-free survival.

CONCLUSIONS

Our study provides specific information on the clinical characteristics and outcome of this uncommon histological subtype of melanoma. However, the pathogenesis remains unknown. Breslow thickness, male gender and amelanosis were significantly associated with a poorer prognosis.

[Wedge excision: a new reconstructive technique after longitudinal nail biopsy]

A biopsy is needed when a solitary melanonychia striata in a white patient remains unexplained after careful clinical examination in order to rule out the development of a malignant melanoma. The ideal biopsy has to excise entirely the lesion and to provide enough tissue for pathological examination. The authors describe a new method of excisional biopsy based on primarily closure using a longitudinal closing wedge osteotomy of the distal phalanx. The longitudinal elliptical resection extended from the distal interphalangeal joint to the hyponychium with en bloc resection of the entire thickness of the nail complex, including the periosteum. A longitudinal closing wedge osteotomy was then performed in the distal phalanx allowing primarily closure with precise alignment of the nailbed edges. After suture of the nailbed, a tension band nail synthesis was performed. Four consecutive melanonychia striata of 2 to 3 mm were consecutively operated on using this technique. Postoperative cares were uneventful in all the cases. The pathological examination confirmed the diagnosis of melanoma in one case, Bowen's disease in one and junctional nevus in two. Cosmetic and functional assessment at a mean follow-up of 12 months evidenced light nail dystrophy in all the cases. Our method offers to the pathologist enough tissue with preserved architecture for precise pathological examination. The technically simple closing wedge osteotomy never complicated the postoperative course. These preliminary results are encouraging and allow us to recommend this technique for the diagnosis of all suspect melanonychia striata between 2 and 3 mm wide.

Acral cutaneous melanoma in caucasians: clinical features, histopathology and prognosis in 112 patients

BACKGROUND

Acral lentiginous melanoma (ALM) is the fourth distinct variant of cutaneous melanoma. The histological diagnosis and prognosis of ALM are still controversial.

OBJECTIVES

To review the features of a large series of patients with ALM, and confirm the validity of the histological criteria for this type of melanoma.

METHODS

A collection of 2642 patients with cutaneous melanoma was recorded during the period 1986-97, among these 187 were located on acral sites. Histological specimens were reviewed in 112 acral melanomas; the following study is based on this subgroup.

RESULTS

Histological examination revealed acral lentiginous melanomas predominantly in palmoplantar and subungual locations (60%), while superficial spreading melanomas (SSM) were found mainly on the dorsal aspects of hands and feet (30%). Nodular melanomas (NM) (9%) occurred in all acral sites. The histological re-examination confirmed the characteristics of ALM as described by Reed in 1976. With increasing tumour thickness nesting of tumour cells and upward migration to the cornified layer was similarly observed. The 5-year survival rate for patients with primary acral melanoma without recognizable metastasis was 82%. ALM differed significantly in survival from SSM (P = 0.001) and lentigo maligna melanoma (P < 0. 001), but survival rates were similar to NM (P = 0.9).

CONCLUSIONS

ALM, as diagnosed by current histological criteria, occur on the palms, soles and subungual sites, and have a poor prognosis.

The clinical significance of oncogene expression in subungual melanoma

Subungual melanoma is a particularly aggressive tumour. However, biological investigations of its behaviour are presently lacking due to its comparative rarity. In order to study the biology of this disease, the activity of the c-myc oncogene was studied in tumours from 24 patients with subungual melanoma using the technique of flow cytometry. High levels of oncoprotein were found in all tumours and exceeded that documented in other varieties of cutaneous melanoma. Survival analysis revealed that stratification of patients according to oncogene activity provided a useful prognostic marker with shorter disease free interval (log rank test, chi 2 = 6.6, P = 0.01) and overall survival (log rank test, chi 2 = 3.6, P = 0.07) in tumours with high oncoprotein levels. This is the first study to investigate oncogene expression in subungual disease and supports its potential application as a prognostic marker.

Plantar melanoma in black South Africans

The outcome of treatment in 40 black patients (27 women, 13 men; mean age 62.9 years) with plantar melanoma over a 13-year period was analysed to evaluate the efficacy of wide local excision with split skin grafting. Substantial delay in seeking medical attention occurred in 35 patients. At presentation, 20 patients had stage I disease, one stage II, 15 stage III and four stage IV. Acral lentiginous melanoma (27 patients) was the most common histological type. The mean Breslow depth was 6.9 mm and 35 patients had lesions of Clark level IV or V. The mean surface area or plantar lesions was 13.3 cm2. Wide local excision with split skin grafting was used in 29 patients; four patients with neglected advanced plantar lesions had below-knee amputation and seven with metastatic disease did not undergo surgery. Graft sepsis occurred in six patients and local recurrence in two. Nine patients were alive at follow-up; the 5-year survival rate was 25 per cent. Delay in presentation and locally advanced disease may explain the poor prognosis of plantar melanoma in black South Africans.

Subungual melanoma: a clinico-pathological study of 24 cases

Twenty-four patients with subungual melanoma (13 women and 11 men) had a mean age of 61.6 years. Twenty-two lesions arose either on the thumb or hallux. The mean delay before diagnosis was 30 months. Two patients presented with stage two melanoma and three of the melanomas were in situ lesions (Clark level 1). Nineteen melanomas were Clark level 4 or 5 and the mean thickness of the invasive melanomas was 4.7 mm. Seven patients died of metastatic disease (mean survival 10 months, range 6-50 months). Clark level, thickness and mitotic activity of the melanomas correlated with poor clinical outcome. Delay in presentation and the presence of advanced disease contribute to the poor prognosis of this tumour.

Melanoma of palms, soles, and nail-beds

The clinical and histological characteristics of palmar, plantar, and subungual melanomas treated in the division of plastic surgery of Helsinki University Hospital between 1970 and 1984 were analysed. The peak incidence was during the seventh decade of life, and the mean delay between the onset of symptoms and the diagnosis was one year. The delay was as much the fault of the physician as of the patient. The observed and relative five-year-survival rates for all 31 patients were 60% and 67%, and the 10-year-survival rates 39% and 49%, respectively. There were 15 cases of the acral lentiginous subtype, and the observed and relative five-year-survival rates were 65% and 71%, and the 10-year-survival rates 48% and 64%, respectively. For the nodular melanomas (n = 11) the survival rates were 53% and 60%, and 39% and 53%, respectively. For the three superficial spreading melanomas they were 50% and 52%, and 25% and 28%, respectively. Microstaging criteria (Breslow and Clark) were both good prognostic indicators. The series was too small for multivariate analysis.

Subungual Melanoma of the Hand

Thirteen patients with subungual melanoma on the fingers had a mean delay before diagnosis of 1.2 years. Four patients presented with local recurrence after inadequate initial treatment and two presented with systemic metastases. Mean primary subungual melanoma thickness was 6.1 mm. and nine patients had Clark level IV or V disease. All patients underwent digital amputation. Two of seven patients who had localised disease initially are alive at 29 and 44 months. One of four patients who had locally recurrent melanoma is alive at 36 months. Both patients with systemic disease at presentation died. Advanced disease and delayed presentation contributed to the poor prognosis of subungual melanoma in our patients.