Acral (volar-subungual) melanoma

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.

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.

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 misdiagnosed as tinea pedis: a case report

The incidence of acral lentiginous melanoma (ALM) varies in different ethnic groups. Volar skin is a relatively infrequent site of malignant melanoma in Caucasian patients, although the foot is the most common site of involvement in Asian and African populations. Diagnosis of ALM is usually delayed and melanomas can be diagnosed at advanced clinical stages, so the prognosis is often poor. We present a Caucasian Turkish man with ALM on the interdigital site of his foot, however, as a result of maceration of the surrounding skin, it seemed to be tinea pedis.

Metastatic malignant melanoma to the foot and ankle: a review of the literature and case report

The lower extremity is a frequent site for malignant melanomas. However, skeletal metastases involving the foot and ankle are a rarity. Nearly all documented cases of secondary pedal bone metastasis have originated from a primary subungual melanoma. The following case study illustrates an unusual skeletal metastasis to the foot and ankle arising from a primary malignant melanoma of the torso.

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.

Melanoma of the hand

Melanomas of the hand are relatively rare, and much confusion exists concerning their pathology and treatment. We reviewed our experience with 39 patients diagnosed with melanoma of the hand. The data were categorized by site, histology, and type of treatment. Most primaries were on the digits, with a few tumors arising on the palm. The most common histology was superficial spreading melanoma, even in the subungual location. Acral lentiginous melanoma accounted for only 8 of 39 cases. Most patients could be treated without radical amputations, even for melanomas on the digits. Review of our patients emphasized the need for early diagnosis. Biopsy of all unexplained pigmented lesions on the hands can lead to early diagnosis, relatively nondeforming treatment, and good survival.

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.

Melanoma of the foot in white South Africans

There have been few studies that have compared the outcome of treatment of melanoma on the sole and dorsum of the foot or defined their prognostic factors. We describe 44 white patients (30 women and 14 men, mean age 53 years) with melanoma on the foot (sole, n = 25, dorsum, n = 19) seen over a 15 year period. Forty patients presented with stage I, two with stage II, one with stage III, and one with stage IV disease. The median Breslow depth of penetration was 2.8 mm (sole 3.3, dorsum 2.3). Of the 40 patients with stage I disease, 34 patients (17 dorsum, 17 sole) were treated by wide local excision (2 cm or more) and none developed local recurrence. Six patients (five sole, one dorsum) who had narrow excision margins (less than 1 cm, stage I disease) developed local recurrences. Ten patients underwent prophylactic hyperthermic limb perfusion. Sixteen patients with stage I disease (10 sole, six dorsum) developed metastases in the inguinal nodes. All 16 underwent block dissection of the nodes and five are alive. The overall survival for both dorsum (73%) and sole (66%) (stage I disease) was similar at 60 months. Both patients with stage II disease were alive at the time of writing, but the two patients with stage III and IV disease had died. The foot is an anatomical subsite associated with a poor prognosis for melanoma. There is little difference in prognostic factors and outcome between the sole and dorsum.

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.

Acral lentiginous melanoma

Between 1958 and 1990, 82 patients with acral lentiginous melanoma were treated by the Tulane Surgical Service with regional perfusion, excision of lesion, and lymph node dissection. The patient group comprised 27 white men, 29 white women, 18 black men, and 8 black women, with an average age of 61 years. More foot lesions than hand lesions were reported, and all the lack men had foot lesions. In stage I patients, overall 5-year survival rates were 65% at 5 years and 44% at 10 years, with differences by race and gender. The black men did poorest, with a 13% 10-year survival rate. Survival rates were worse with increasing disease stage when calculated using univariate analysis. The 5-year survival rate of all patients with stage III and stage IV disease was 26%. A multivariate analysis was performed in 78 of 82 patients in whom all variables of Clark's level, age, race, stage, and sex were known. A strong relationship was observed between decreasing survival time and increasing Clark's level, with stage of marginal significance. In a multivariate analysis of patients with stage I disease, an increasing level of invasion was found to be significant, with a trend for a relationship to thickness. A trend toward decreased survival time was observed in men and blacks.

Improvement in survival rate of patients with acral melanoma observed in the past 22 years in Sendai, Japan

While the incidence of malignant melanoma is much lower in Japanese than in Caucasians, the commonest site of melanoma in Japanese has been reported to be the acral regions of the limbs. The survival rate for acral and nodular melanoma observed at the Department of Dermatology, Tohoku University Hospital in Sendai, Japan from 1969 to 1990 was reviewed. Among 150 melanoma patients 125 (83%) and 17 (11%) had primary cutaneous melanoma and mucous membrane melanomas, respectively. Frequent sites for cutaneous melanomas were the sole (31%) and subungual regions (15%). Comparison of the stages of plantar melanoma at diagnosis showed that the proportion of stages III and IV decreased after 1980 with a corresponding increase in those with a tumour thickness of less than 4 mm (stage II). Concurrently, the prognosis of plantar melanoma has improved; the 5-year survival rate in each of the three periods 1969-75, 1976-80 and 1981-85 was 21, 70 and 90%, respectively. This was also the case with subungual melanoma. Such improvements in the prognosis are thought to be mainly due to early detection through the growing public awareness of this life-threatening disease. By contrast cases of nodular melanoma increased sharply after 1980. Among these, the high proportion of patients in advanced stages (stages III and IV) remained static even after 1980, with a resultant low 5-year survival rate in the above mentioned periods of 33, 38 and 18%, respectively.

Plantar malignant melanoma in a white Caucasian population

Fifty-one white Caucasian patients from the west of Scotland, with stage I primary malignant melanoma arising on the plantar surface were studied. Subungual lesions were excluded from the study. Clinical and pathological features were related to survival, and compared with a group of 239 cases of clinical stage 1 melanoma of the lower limb, excluding the foot, collected in the same geographical area over the same period of time (1979-84). The average age of patients with plantar melanoma was 67 years and was significantly older than those with leg melanomas, in whom the mean age was 53 years. Twenty patients with plantar lesions had superficial spreading melanomas, 27 had acral lentiginous melanomas, and four had nodular lesions. The female:male ratio was 3:2 which was significantly different from the 7:1 female:male ratio for leg lesions. Plantar melanomas were more commonly ulcerated (57%) than were melanomas on the leg (29%) [P < 0.001]. There was no significant difference between the mean thickness of melanomas on the plantar surface and those on the leg. Nine (17%) of the patients with plantar melanomas gave a clinical history of pre-existing naevus and in 27% there was pathological evidence of a pre-existing naevus. Disease-free survival at 5 years for the population with plantar melanomas was 82, 51 and 0%, respectively, for melanomas 0-1.49, 1.5-3.49 and over 3.5 mm in thickness. This compares with 95, 71 and 46%, respectively, for leg lesions. In each thickness category patients with leg melanomas have a significantly better survival.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Acral melanoma: a review of 185 patients with identification of prognostic variables

One hundred eight-five patients with acral melanoma treated since 1972 were reviewed. These included 53 subungual lesions, 123 plantar lesions, and 9 palmar lesions. Eighty percent presented with stage I disease. Mean age was 57 years. Males outnumbered females 1.1:1. Seventeen percent (17%) were blacks. Actuarial 10-year survival was 58% for stage I patients and 35% for stage II patients. Univariate Cox regression analyses identified 5 prognostic variables affecting survival: stage at diagnosis (P less than 0.001), race (P less than 0.001), ulceration (P = 0.012), Clark's level (P = 0.014), and thickness of the primary lesion (P = 0.013). Factors unrelated to survival included sex of the patient, site (volar vs. subungual), histology, and treatment with amputation. Multivariate analysis for patients with stage I lesions identified race (P = 0.001) and ulceration (P = 0.018) as significant variables, with thickness approaching significance (P = 0.094). In an additional series of 71 patients with melanomas arising from extremity sites near the junction of glabrous and non-glabrous skin, survival was significantly poorer for those arising from glabrous skin (P = 0.024), and reflects a higher incidence of metastatic disease at diagnosis. Specific active immunotherapy was the principal adjuvant used for these patients, and survival was comparable to that reported with regional perfusion therapy. Acral melanoma a) has a strong racial predilection, b) carries a grave prognosis, and c) arises from glabrous skin. It is a clinical entity distinct from other extremity melanomas. Surgical management with either wide excision or amputation is appropriate for the primary lesion.

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.

Acral melanoma. A clinicopathologic study of 28 patients

Clinical and histopathologic analyses of 28 cases of acral melanoma in the last 24 years were carried out in this study. Of our 81 patients with cutaneous malignant melanoma, 28 (35%) had acral melanoma. The mean patient age was 59 years old. The two most commonly involved sites were the soles and toes. The preferential sites for metastasis were the lymph nodes, followed by the lungs, bone, and liver in descending order. Histologically, all skin biopsy specimens showed biphasic growth patterns and consisted of either spindle cells or epithelioid cells or both. The treatment was in all cases mainly surgical and, in patients at advanced stage, chemotherapy was added. The mean survival time for the series was 34.03 months, while the 3-year survival rate was only 29%.

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

We have retrospectively reviewed the charts of 34 acral melanoma patients (melanoma arising from the volar skin of the hands, feet or a subungual site) seen in the Auckland area between 1970 and 1985. These 34 patients constituted 3.5 per cent of the total number of patients (972) reviewed over this period. Six of the thirty-four patients were either Polynesian or Maori. There were 19 men and 15 women, and the mean age of the group was 59 years. The primary lesion arose from the plantar or palmar skin in 25 patients and 9 patients had subungual lesions. All lesions but one were pigmented. Most patients with plantar or palmar lesions presented with clinical stage 1, Clark's level 4 disease, while those with subungual lesions presented most commonly with stage 2, Clark's level 5 disease. Treatment was wide local resection for plantar and palmar lesions and amputation for subungual lesions. Regional lymph node dissection was performed in 10 patients with positive nodes at presentation and in 6 patients who developed metachronous nodal disease. Patients were followed for between 1 and 16 years, and 18 patients died in this period, 15 of metastatic melanoma (mean time 34 months). Subungual melanoma carried a worse prognosis than melanoma arising in palmar or plantar skin.