Subungual melanoma: a clinico-pathological study of 24 cases

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.

Slow Mohs micrographic surgery for nail apparatus melanoma in situ

BACKGROUND

Nail apparatus melanoma is a malignant tumor with a high incidence in Chinese melanoma patients. Slow Mohs micrographic surgery is an emerging technique for treating nail apparatus melanoma in situ (NAMIS).

OBJECTIVE

This study evaluated the efficacy and safety of slow Mohs micrographic surgery for treating NAMIS.

METHODS

Patients were enrolled in this retrospective study and treated in a single center from October 1, 2016, to June 30, 2022. Each patient underwent standard slow Mohs micrographic surgery, and follow-up was regularly conducted at clinics.

RESULTS

Ten patients were enrolled in the study. Two patients underwent one Mohs stage, seven underwent two Mohs stages, and one underwent seven Mohs stages. The resection margin ranged from 5 to 25 mm. No severe complications were reported in the treatment, and recurrence of NAMIS was not observed during the follow-up period.

CONCLUSION

Slow Mohs micrographic surgery is a valuable surgical method to treat NAMIS that preserves digit function and can be well tolerated by patients.

Different progression pattern between acral and nonacral melanoma: A retrospective, comparative, clinicoprognostic study of 492 cases of primary cutaneous melanoma according to tumor site

BACKGROUND

There are limited data regarding the difference in progression pattern between acral melanoma and nonacral melanoma.

AIMS

The objectives of this study were to compare the progression pattern between acral and nonacral melanoma and evaluate its impact on clinical outcomes.

METHODS

Clinical and histopathological features, survival outcomes and prognostic factors of 492 patients with acral melanoma or nonacral melanoma were retrospectively evaluated using the Asan Medical Center database.

RESULTS

The male-to-female ratio and the mean age was 1:0.92 and 60.2 years for acral melanoma (n = 249), and 1:0.85 and 58.4 years for nonacral melanoma (n = 243), respectively. The demographic difference was not significant. Although prediagnosis duration was longer and the advanced stage was more common in acral melanoma than that in nonacral melanoma, the vertical growth phase was more common in nonacral melanoma than that in acral melanoma, whereas, the horizontal diameter is longer in acral melanoma than that in nonacral melanoma. Dissemination to lymph nodes was more common in acral melanoma than that in nonacral melanoma. Lymph node involvement was associated with deeper Breslow thickness in nonacral melanoma but not in acral melanoma. The degree of correlation of prediagnosis duration with horizontal diameter was remarkable in acral melanoma, but with Breslow thickness in nonacral melanoma. Overall survival was worse in acral melanoma than that in nonacral melanoma. The prognostic value of Breslow thickness was more remarkable in nonacral melanoma than that in acral melanoma.

LIMITATIONS

This study is a retrospective, single-center design.

CONCLUSION

Acral melanoma has a longer radial growth phase compared with nonacral melanoma. However, acral melanoma is commonly associated with lymph node dissemination which contributed to worse survival in acral melanoma than nonacral melanoma.

Retrospective analysis of nail biopsies performed using the Medicare Provider Utilization and Payment Database 2012 to 2017

Subungual melanoma (SUM) is subset of acral melanoma that develops within the nail unit and is associated with a poor prognosis. Nail biopsy is the only way to definitively diagnosis SUM. Our objectives were to analyze the Medicare database for nail biopsy utilization and to compare the annual nail biopsy rate with the estimated incidence of SUM in the United States. A retrospective study on nail biopsy data was performed using the Medicare Provider Utilization and Payment Database 2012 to 2017. The number of nail biopsies performed per 100 000 people was compared to SUM incidence per 100 000 people. Podiatrists, dermatologists, other physicians, and NP/PAs respectively performed 12.12, 0.42, 0.08, 0.07 nail biopsies per 100 000 people annually. Dermatologists performed adequate nail biopsies to cover the minimum (0.7%), but not the maximum (3.5%) estimated incidence of SUM. Only 0.28% and 1.01% of general dermatologists and Mohs surgeons, respectively, performed nail biopsies in 19/50 (38.00%) states and 69/929 (7.42%) zip codes. Limitations of our study were that nail biopsies on patients less than 65 years, and those with no or commercial health insurance were not analyzed. In sum, very few dermatologists performed nail biopsies in the Medicare database. Increased efforts are needed to educate dermatologists on nail surgery.

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 lentiginous melanoma in the Turkish population and a new dermoscopic clue for the diagnosis

Background

The incidence of acral lentiginous melanoma (ALM) in the white population is low. Dermoscopy enhances diagnosis of ALM; however, diagnostic accuracy may sometimes be poor due to the considerable proportion of amelanotic ALM variants.

Objectives

To calculate the proportion of ALM among all melanoma subtypes and to determine the frequency of dermoscopic features of ALM in the Turkish population.

Methods

Out of 612 melanomas, there were 70 cases of ALM, of which 46 showed sufficient image quality for retrospective study of dermoscopic features. Data from patients and their lesions was classified according to clinical features and histopathologic parameters. The dermoscopic variables evaluated were based on pertinent literature on dermoscopy of acral melanocytic neoplasms.

Results

The prevalence of ALM among all melanoma subtypes was 11.4%. Parallel-ridge pattern (PRP) was detected in 60.8% of cases and irregular diffuse pigmentation (IDP) in 28.3%. The ALMs were amelanotic in 24%, showing an atypical vascular pattern in all cases; a new dermoscopic pattern, named “vascularized parallel-ridge pattern” (VPRP), was detected in 13% of ALMs. Irregular lines were observed in 81.8% of subungual melanomas and were often associated with a multicolored background.

Conclusions

ALM has site-specific dermoscopic patterns, with PRP being the most prevalent pattern. The newly described VPRP pattern may be an additional clue for ALM diagnosis, especially in thin amelanotic melanomas.

Congenital longitudinal melanonychia: a case report

Congenital longitudinal melanonychia is rarely seen in Caucasians and poses a diagnostic dilemma. It is characterized by the presence of hyperpigmented brown or black streaks visible in the nail plate. We present the case of 20-month-old boy with congenital longitudinal melanonychia, the diagnostic procedure, and management. Dermatoscopy of the nail revealed dark brown linear hyperpigmented lines in the nail plate with an irregular color. The diagnosis of a congenital nail matrix nevus was established on clinical grounds. A wait-and-see policy was taken. A biopsy was not performed because the cause of longitudinal melanonychia is essentially benign, especially in the congenital form. Subungual melanomas are very rare and mostly appear in middle-aged patients. Clinical, dermatoscopic, and histopathological guidelines that could directly distinguish between a benign nail matrix nevus and malignant subungual melanoma in the pediatric population have not been confirmed yet. The diagnostic dilemma therefore remains open.

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.

Nail apparatus melanoma: is trauma a coincidence? Is this peculiar tumor a real acral melanoma?

Nail Apparatus Melanoma (NAM) is rare, particularly in Caucasians. Understanding its pathogenesis and collecting epidemiologic data may be difficult due to its location and the exiguity of the case series of this cancer. Cutaneous melanoma has been thought related to UV radiation, and NAM is considered an acral variant of melanoma, even if the nail presents a specific anatomy. Little is reported about pathogenesis, except reports suggesting traumatic injuries as a causal factor. UV exposure is debated in nail melanoma because of its structure. The nail is, in fact, a unique structure with sun-exposed and non exposed melanocytes. NAM arises from the nail melanocytes, located in the nail matrix, which is the germinative part of the nail and composed of a proximal and distal portion. The proximal nail matrix lays under the proximal nail fold that covers it and is non-sun exposed, while the distant nail matrix, clinically visible as the lunula, is sun-exposed, though lying underneath the nail plate. According to these anatomical data, NAM is a distinct melanoma type, and studies need to classify it as acral melanoma or as a particular type of melanoma with its own pathogenesis and prognostic criteria. This study investigates potential risk factors of NAM, emphasizing (i) trauma and (ii) UV exposure among our NAM patients.

Relearning the lesson -- amelanotic malignant melanoma: a case report

Although not as common as the other melanomas, amelanotic melanoma often evades diagnosis by masquerading as other pathology. A high index of suspicion is therefore required for early and appropriate intervention. We present a patient who was diagnosed and managed as having paronychia of the middle finger while in actual fact he had a subungual amelanotic melanoma. By the time of his referral to the orthopaedic team it had progressed to an advanced stage. Our case underlies the importance of early recognition and referral of this rare but malignant lesion by primary care physicians.

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.

Mise au point sur la prise en charge chirurgicale du mélanome malin cutané. Revue de la littérature

Nowadays managing a cutaneous malignant melanoma can concern different kind of physicians: dermatologists, general or plastic surgeons The primary surgical procedure is a major step of the treatment. Biopsy must be total to properly determine the thickness of the tumor in case of malignancy. Wide local excision of the scar is often necessary to decrease the local and general recurrence rates. Wide local excision must be performed conforming to its own surgical rules. Managing tumor located on the face or limb extremities is a matter of plastic surgery. Sentinel node biopsy has succeeded to elective lymph node dissection. This procedure allows research of lymphatic spreading of the disease. Practice of sentinel node biopsy must be achieved in a protocolar way. Topography of the lesion can modified achievement and results of this procedure. Prognosis benefit of sentinel biopsy is now clear. Elective lymph node dissection is only performed in case of invaded sentinel node or clinically invaded lymph nodes. Local or locoregional recurrences mainly respond to surgical treatment using wide excision. However, alternative solutions are being evaluated (isolated limb perfusion).

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.

Regressed subungual melanoma simulating cellular blue nevus: managed with sentinel lymph node biopsy

BACKGROUND

Subungual melanoma, a not uncommon presentation of cutaneous melanoma in Asian populations, is easily overlooked as benign and thus is improperly treated.

OBJECTIVE

To present two cases with clinical suspicion of subungual melanoma. Skin biopsies failed to demonstrate the diagnostic features of malignancy.

METHODS

Lymphoscintigraphy and sentinel lymph node (SLN) biopsies were performed to determine regional lymph node status.

RESULTS

Both hematoxylin-eosin and HMB45 staining revealed melanoma cells in the SLN of the patient. The second patient's SLN was negative for malignant cells, but her excised primary lesion showed extensive regressed melanoma.

CONCLUSION

Regression phenomena are not uncommon for subungual melanoma. An extention biopsy techniques are useful for determining nodal basin status in regressed subungual melanoma.

Concomitant traumas influence prognosis in melanomas of the nail apparatus*

BACKGROUND

In nail apparatus melanomas (NAM), the role of standard melanoma prognostic factors is under discussion. The prognostic influence of traumas to the clinically apparent tumour has not been sufficiently examined.

OBJECTIVES

To estimate the influence of traumas against the background of standard prognostic factors on the course of NAM.

METHODS

In 33 patients (20 women, 13 men, median age 65.0 years) with NAM (median tumour thickness 3.5 mm), we retrospectively examined a detailed history of trauma to the affected extremity at first presentation. Histological or other standard prognostic factors and follow-up were studied prospectively using a standardized protocol.

RESULTS

Of 33 patients, 21 had suffered injury to the clinically apparent melanoma primary between 4 and 72 months prior to definitive surgical treatment (diagnostic biopsy up to 3 months ahead of excision of the melanoma was not considered). Eight of these patients had undergone inadequate therapy procedures. In Kaplan-Meier analysis, trauma to the clinically apparent tumour and tumour thickness were found to be significant prognostic factors for recurrence-free survival, and trauma to the clinically apparent tumour, Clark level and tumour thickness were significant prognosis predictors for overall survival. In Cox's proportional hazards model, trauma to the clinically apparent tumour was found to be a significant and independent risk factor with regard to overall survival (hazard ratio 5.39; P = 0.029). An influence of trauma on the primary pathogenesis of NAM could not be confirmed. Only three patients reported trauma prior to the onset of tumour.

CONCLUSIONS

From our data, trauma to the clinically apparent tumour might be a considerable risk factor in NAM. The diagnosis of NAM should be considered in lesions of the nail apparatus and further deterioration of the prognosis due to inadequate therapeutic attempts or injury to the NAM should be avoided.

Survival of patients with primary pedal melanoma

Malignant melanoma is increasing at a rate faster than any other cancer in the United States. Location of the primary tumor on the foot is associated with poorer prognosis. This study evaluates a cohort of 148 patients with melanoma of the lower extremity (37 foot or ankle and 111 leg, knee, or thigh) diagnosed at a university medical center during a 32-year period. The mean follow-up for the foot/ankle patients was 44 months. The overall 5-year survival rate was 52% for patients with a primary melanoma of the foot/ankle compared with 84% for patients with a primary melanoma elsewhere on the lower extremity. Although the study period extended over 32 years, nearly 65% of the foot/ankle patients were diagnosed in the last decade. This increase is most likely because of the documented increase in incidence of melanoma in the United States and an increasing referral pattern at our institution.

"Functional" surgery in subungual melanoma

BACKGROUND

Subungual melanomas represent approximately 2% to 3% of cutaneous melanomas in White populations. Complete or partial amputation proximal to the distal interphalangeal joint of the digits has been suggested. Recently, we introduced for acral melanomas, similar to lentigo maligna melanoma, limited excision and complete histology of excisional margins (three-dimensional histology).

OBJECTIVE

To evaluate the prognostic relevance of clinical parameters and different surgical management in patients with subungual melanoma.

STUDY DESIGN

From 1980 to 1999, subungual melanoma was diagnosed in 62 of 3,960 stage I and II melanoma patients (1.6%) of the melanoma registry of the Department of Dermatology (University of Tuebingen). A retrospective comparative analysis of two treatment groups was performed: Thirty-one patients had an amputation in or proximal to the distal interphalangeal joint (median follow-up of 55 months), and 31 patients had "functional" surgery with local excision of the tumor and only partial resection of the distal phalanx (median follow-up of 54 months).

RESULTS

In the univariate analysis, the level of invasion (P=0.0059), ulceration (P=0.0024), and tumor thickness (P=0.0004) were significant prognostic factors for recurrence-free survival but not for survival. In a multivariate analysis, only lower tumor thickness and a reduced level of amputation were independent significant prognostic parameters for recurrence-free survival (P=0.035 and P=0.0069). Patients with an amputation in or proximal to the distal interphalangeal joint did not fare better than patients with less radical "functional" surgery.

CONCLUSION

Limited excision with partial resection of the distal phalanx only and three-dimensional histology to assure tumor-free resection margins give better cosmetic and functional results and do not negatively affect the prognosis of patients with subungual melanoma.

Tumors of the perionychium

Tumors of the perionychium are often subtle and difficult to diagnose. Because they are somewhat uncommon, the early symptoms of these tumors, which may include vague pain, local swelling, nail discoloration, nail deformity, or drainage, may be mistaken for signs of infection and/or trauma and therefore treated with topical or oral antibiotics for some time. Functionally important in enhancing fingertip sensation, protection, and manipulating fine objects, the perionychium is continuously subject to day-to-day trauma and injury that can alter the natural contours and growth patterns of the nail plate. Bacterial, viral, or fungal infections can incite swelling, pain, and distortion of the perionychium as well. Both infection and trauma, then, can mask underlying tumors or growths that would delay their diagnosis. A delay in treatment can be devastating if the growth of the perionychium happens to be malignant. Therefore, a general understanding of the signs and symptoms of the perionychium tumors is needed by all physicians and surgeons treating nail problems.

Longitudinal melanonychia

BACKGROUND

Ungual melanoma is the most serious disease affecting the nail. The majority start with a longitudinal brown streak in the nail.

OBJECTIVE

To outline the different nail pigmentations, their differential diagnoses, treatment, and prognosis.

METHOD

Clinical and histologic evaluation of dark nail pigmentations.

CONCLUSION

Brown to black nail pigmentation may be due to different coloring substances of exogenous and endogenous origin. Exogenous pigmentations usually are not streaky or do not present as a stripe of even width with regular borders. Bacterial pigmentation, most commonly due to Pseudomonas aeruginosa or Proteus spp., have a greenish or grayish hue and the discoloration is often confined to the lateral edge of the nail. Subungual hematoma may result from a single heavy trauma or repeated microtrauma which often escapes notice. The latter is usually found on the medial aspect of the great toe. Although oval in shape, it commonly does not form a neat streak. Melanin pigmentation in the form of a longitudinal streak in the nail is due to a pigment-producing focus of melanocytes in the matrix. Neither the color intensity nor the age of the patient are proof of benignity or malignancy although subungual melanomas are very rare in children and malignant longitudinal melanonychia is usually wider than 5 mm. Hutchinson's melanotic whitlow, nail dystrophy, and a bleeding mass strongly suggest malignancy. Treatment is as conservative as possible in order to keep the tip of the digit; once the melanoma is completely removed, amputations have not been shown to prolong the disease-free survival time.

Nail apparatus melanoma

Nail apparatus melanoma is a relatively rare variant of melanoma with a disproportionately high mortality when compared with melanoma elsewhere. The aetiology and natural history remain poorly understood. There is no clear epidemiological association with race, skin type or sun exposure. Universally accepted clinical and histological criteria for the diagnosis of early nail apparatus melanoma have not been defined. The two cardinal clinical signs are melanonychia striata and Hutchinson's sign. These are useful but not pathognomonic of melanoma. Diagnostic delay is frequent and patients commonly have advanced disease at the time of diagnosis. Surgical excision is advocated for treatment of stage I disease; however, the most appropriate re-excision margins, including the level of amputation where required, have not been determined. Early diagnosis and excision of the tumour is the only treatment known to increase survival. Adjuvant systemic chemotherapy, isolated limb perfusion, and routine elective lymph node dissection have been used, but no survival benefit has been demonstrated.

Nail melanoma: a review of the literature with recommendations to improve patient management

In this review, the current state of knowledge concerning nail melanoma is summarized. The pathogenesis, histological findings, clinical presentation, treatment and prognosis of this rare form of cutaneous melanoma are discussed. Important clinical clues to the early diagnosis of nail melanoma are highlighted and recommendations to improve the management of patients are suggested.

Clinicopathological characteristics of melanomas of the hand

A 25-year clinicopathological review of 19 patients with malignant melanoma of the hand is reported. There were 11 women (median age 73 years) and eight men (median age 70 years). Eleven tumours were subungual, six on the dorsum of the hand, and two had a palmar location. Seven tumours were acral lentiginous melanomas, six were superficial spreading melanomas, and five were of the nodular subtype. Eleven patients presented with localized disease (clinical stage I), four with local spread (clinical stage II), and four with regional lymph node metastases (clinical stage III). Nine of the patients have died of the disease, with a median survival time of 30 months (range, 10-84 months). The subungual melanomas were thicker and the patients were older at presentation compared with the non-subungual sites. Review of our patients emphasized the need for early diagnosis.

Subungual malignant melanoma of the hand: unusual clinical presentation. Case report

A 75-year-old woman presented with a four month history of a slowly growing tumour on the distal portion of the third finger of her left hand. The lesion suggested clinically an inflammatory process or an epidermoid carcinoma. The finger was amputated through the proximal interphalangeal joint. Microscopic examination showed an acral-lentiginous melanoma, subungual type (Clark level V). No elective lymph node dissection was done, and no prophylactic chemotherapy was given. The patient remains free of disease eight months after operation. Clinicians should be aware of this rare lesion, which may mimic other benign or malignant conditions.

The incidence and prognosis of nail apparatus melanoma. A retrospective study of 105 patients in four English regions

Our population-based study establishes epidemiological data on age-specific incidence rates, clinical presentation, Breslow microstaging, treatment and survival of nail apparatus melanoma (NAM) patients in England. Four cancer registries, covering a population of 10.6 million, recorded 105 cases of NAM during the period 1984-93. During the same decade there was a total of 7585 patients with cutaneous melanoma and NAM represents 1.4% of all cutaneous melanoma. The incidence rate of NAM in English patients is 0.1 per 100,000 of the population per annum. Amelanotic melanoma was the clinical presentation in 24 of our NAM cases. The overall prognosis is poor with an observed 5 year survival of only 51%. Patients with NAM less than 2.5 mm Breslow depth have a 5 year survival of 88% and are twice as likely to survive compared with those with tumours greater or equal to 2.5 mm in thickness (P < 0. 05). NAM patients are best managed by a multidisciplinary team approach in a few key skin cancer centres.

Subungual melanoma of the hand

Subungual melanoma is a rare but well-recognized tumor of the hand. Its management is ill defined and the factors influencing prognosis have not been well described. The clinicopathologic features of a series of 38 patients with subungual melanoma of the hand are reported. The median thickness was 3 mm, and only seven patients presented with pathologic stage I disease (American Joint Committee on Cancer [AJCC] system). Ulceration and lack of pigmentation were the only significant univariate prognostic indicators. There was no significant difference in local recurrence rates among patients whose amputation was carried out proximal or distal to the interphalangeal joint of the thumb or the middle of the middle phalanx in the other fingers. Management of the regional lymph node field based on the use of selective lymphadenectomy is described.

Pathologic fracture secondary to subungual melanoma

Subungual melanoma is uncommon, and delays in diagnosis and misdiagnosis occur frequently. We describe a 61-year-old black male who presented with a non-healing area in his left thumb nailbed with many of the features of subungual melanoma. However, the patient also had a pathologic fracture of the distal phalanx, leading to some initial confusion about the diagnosis. Despite aggressive multimodality therapy, the disease rapidly progressed, resulting in the patient's death. Pathologic fracture due to subungual melanoma may indicate a particularly poor prognosis.

Malignant melanoma of the foot and ankle

The records of sixty patients who had a malignant melanoma of the foot or ankle were reviewed retrospectively to determine the clinical features, prognostic factors, and distinguishing characteristics. Fifty-seven patients were white and three were black. There were forty-two women and eighteen men (a female-to-male ratio of 2.3 to 1). The mean age at the time of presentation was fifty-seven years (range, twenty-two to eighty-three years). The most common site of involvement was the plantar aspect of the foot. The mean duration of follow-up was forty-five months (range, three to 144 months). Kaplan-Meier life-table analysis revealed an over-all five-year survival rate of 63 per cent and an over-all ten-year survival rate of 51 per cent. The mean duration of survival for the patients who had a plantar or subungual lesion was significantly shorter than that for the patients who had a lesion at another site on the dorsal aspect of the foot or on the ankle (forty-seven compared with seventy-two months) (p = 0.02). The mean depth of the lesion, according to the criteria of Breslow, was 3.03 millimeters, and the mean level, according to the classification of Clark et al., was IV. According to the classification of the American Joint Commission on Cancer, forty-three patients had stage-I or II (local) disease, thirteen had stage-III disease (nodal or in-transit disease, defined as cutaneous or subcutaneous metastases more than two centimeters from the primary tumor but not beyond the regional lymph nodes), and four had stage-IV disease (distant visceral metastases) at the time of presentation. Lesions at plantar and subungual sites were also associated with a higher prevalence of clinical misdiagnosis compared with lesions on the dorsal aspect of the foot or on the ankle (p = 0.02). The misdiagnoses included a benign nevus (one patient), a paronychia (one patient), a pyogenic granuloma (two patients), a plantar wart (three patients), a ganglion cyst (one patient), a blister (two patients), and a traumatic lesion (five patients).(ABSTRACT TRUNCATED AT 250 WORDS)