Acral Melanocytic Lesions Research Articles

Validation of a Dermatoscopy-Based Algorithm for the Diagnosis of Acral Melanoma

Introduction: Diagnosis of acral melanocytic lesions can be challenging. The BRAAFF checklist was introduced as a tool to help differentiate between acral nevi and melanoma but has not been validated. Methods: We asked raters with varying expertise in dermatoscopy to diagnose dermatoscopic images of 533 acral nevi and 144 melanomas via an online platform with and without use of the BRAAFF checklist. From the ratings, we calculated sensitivity, specificity, and interrater agreement. Additionally, a new simplified version of the checklist was also tested. Results: We collected 6,880 ratings from 175 readers. The BRAAFF checklist achieved a sensitivity of 92.5% and a specificity of 65.0%, which was similar to diagnosis from pattern recognition (sensitivity 90.0%, specificity: 72.1%). Interrater agreement for the BRAAFF criteria ranged from fair to moderate, with lowest agreement for parallel ridge and fibrillar pattern (alpha = 0.31) and highest for asymmetry of colors and structures (alpha = 0.46). Agreement and diagnostic accuracy were higher for more experienced readers. A simplified version with only two criteria achieved similar sensitivity (95.0%) and lower specificity (60.0%) as the original BRAAFF checklist. Conclusion: The BRAAFF checklist is a useful tool for the diagnosis of melanocytic acral lesions with acceptable sensitivity and reasonable specificity but is not superior to pattern recognition. A simplified version of the checklist could be easier to use with equal sensitivity while exhibiting a modest reduction in specificity.

Acral Melanocytic Nevi in a High-Risk Population: Prevalence, Clinical Characteristics and Dermatoscopic Patterns

Background: The prevalence of acral nevi and their dermatoscopic patterns have been mainly studied in Asian populations. Few data exist on the prevalence and clinico-dermatoscopic morphology of acral nevi in white populations. Objectives: The aim of this study was to assess the prevalence of acral nevi and evaluate their features in a cohort of Caucasian individuals at high risk for skin cancer. Methods: We prospectively examined the palms and soles of 680 high-risk patients who underwent total body clinical and dermatoscopic documentation, as a part of their routine follow-up, between January 2016 and March 2020 at a skin cancer referral center in Greece. Results: Overall, 334 acral lesions were detected in 217 (37.0%) of 585 patients in the study. The presence of acral nevi was associated with 2.6 higher odds of a total nevus count higher than 50 (OR: 2.6, p < 0.05, confidence intervals [CI]: 1.11–6.09). Of 334 acral nevi, 65.0% were clinically flat and 35.0% were clinically palpable. Palpable lesion had 19-fold higher probability of being located on the sole (OR: 19.44, p < 0.05, CI: 3.91–96.7). The parallel furrow pattern was present in 147 lesions (44.0%). In 76 lesions (22.8%), we observed a previously undefined pattern consisting of wavy lines, which was correlated with clinically palpable lesions (p < 0.001). The third most common pattern was homogeneous (10.5%), followed by the fibrillar (8.7%), the lattice-like (7.2%), the reticular (3.6%), and globular (3.3%). Conclusion: We observed a higher prevalence of benign acral melanocytic lesions than expected, probably related to our cohort selection of patients at high risk for developing skin cancer. Our study confirms the previously described dermatoscopic patterns and provides novel insights into the dermatoscopic morphology of acral palpable nevi, for which we described a new benign pattern consisting of wavy lines.

Application of fluorescence in situ hybridization in distinguishing acral melanoma in situ from acral junctional melanocytic nevus on the volar skin in Japanese patients.

Four-colored fluorescence in situ hybridization (FISH) is an ancillary diagnostic tool for melanoma. However, most studies that have investigated the usefulness of FISH primarily focused on advanced melanomas. The aim of the current study was to evaluate the effectiveness of FISH in distinguishing acral melanoma (AM) in situ from benign acral junctional nevus (AJN), two types of lesions that are difficult to differentiate via traditional clinical means. The authors investigated the usefulness of FISH in 91 acral melanocytic lesions, including 50 lesions with diagnostic discrepancies between dermoscopic and pathologic approaches or difficulty diagnosing between AM in situ and AJN, on the volar skin of Japanese patients. The authors classified the lesions based on the diagnosis of dermatologists and pathologists into four groups: (I) lesions with a unanimous diagnosis by dermatologists and pathologists as AM in situ or AJN (n=41); (II) lesions with a unanimous diagnosis by dermatologists only as AM in situ or AJN (n=21); (III) lesions with a unanimous diagnosis by pathologists only as AM in situ or AJN (n=15); and (IV) all other lesions (n=14). The dermatologists diagnosed the lesions by clinical and dermoscopic photographs alone, while the pathologists diagnosed the lesions by microscopy of hematoxylin and eosin-stained slides alone. In group I (AM in situ [n=20] and AJN [n=21]), four-colored FISH demonstrated 90% sensitivity and 81% specificity in distinguishing AM in situ from AJN. There was a significant correlation between the FISH results and the unanimous diagnoses by pathologists alone (p=0.03) in group III. However, FISH results were not significantly correlated with the unanimous diagnoses by dermatologists alone (p=0.33) in group II. In conclusion, the four-colored FISH probe kit was useful in distinguishing between AM in situ and AJN and may be an ancillary method when pathologists who are not experts of dermatopathology diagnose melanocytic lesions.

Dermoscopy for Acral Melanocytic Lesions: Revision of the 3-step Algorithm and Refined Definition of the Regular and Irregular Fibrillar Pattern.

Citation: Saida T, Koga H, Uhara H. Dermoscopy for acral melanocytic lesions: Revision of the 3-step algorithm and refined definition of the regular and irregular fibrillar pattern. Dermatol Pract Concept. 2022;12(03):e2022123. DOI: https://doi.org/10.5826/dpc.1203a123

Diagnostic utility of PRAME expression by immunohistochemistry in subungual and non-subungual acral melanocytic lesions.

The immunohistochemical (IHC) marker PReferentially expressed Antigen in MElanoma (PRAME) has shown promise in the diagnosis of melanocytic lesions. A few studies have investigated PRAME IHC expression in acral melanomas, but PRAME expression in subungual melanomas is largely unknown. We evaluated the utility of PRAME IHC expression in distinguishing subungual melanomas (SUM) and non-subungual acral melanomas (AM) from acral nevi (AN). Twenty-two SUM, 20 AM, and 14 AN were identified. IHC studies were performed using an anti-PRAME antibody. The percentage of lesional cells with PRAME expression was recorded and categorized as follows: 0%, 0; 1%-25%, 1+; 26%-50%, 2+; 51%-75%, 3+; and >75%, 4+. Patient demographics and other relevant clinicopathologic parameters were recorded. Diffuse (4+) PRAME IHC expression was identified in 55% (12/22) SUM and 70% (14/20) AM, respectively. Any PRAME expression (1+ to 4+) was identified in 73% (16/22) SUMs and 95% (19/20) AM, respectively. One of 14 (7%) AN exhibited PRAME expression; interestingly, the pattern of expression was diffuse. In our study, PRAME IHC expression was useful in identifying AM, including SUM. However, there are exceptions of PRAME-negative melanomas and PRAME-positive nevi.

CCND1 copy number increase and cyclin D1 expression in acral melanoma: a comparative study of fluorescence in situ hybridization and immunohistochemistry in a Chinese cohort

BackgroundCCND1 copy number increase is characteristic of acral melanoma and is useful in distinguishing benign and malignant acral melanocytic lesions. Increase of the gene copy number may result in protein overexpression. This raises the possibility that detection of high expression of cyclin D1 by immunohistochemistry (IHC) may be used as a surrogate for direct evaluation of increase in the CCND1 gene copy number.MethodsWe examined increases in CCND1 copy number with fluorescence in situ hybridization (FISH), and examined cyclin D1 protein expression with IHC in 61 acral melanomas.ResultsUsing FISH, 29 acral melanomas (29/61, 47.5%) showed increase in the CCND1 copy number, including 8 (8/61, 13.1%) which showed low-level increase in the CCND1 copy number and 21 (21/61, 34.4%) with high-level increase in the CCND1 copy number. By analysis of IHC, the median IHC score was 15% (range: 1–80%) in acral melanomas with no CCND1 copy number alteration. In acral melanomas with low-level CCND1 copy number increase, the median IHC score was 25% (range: 3–90%). In acral melanomas with high-level CCND1 copy number increase, the median IHC score was 60% (range: 1–95%). Comparing FISH and IHC, cyclin D1 protein expression level has no corelation with the CCND1 copy number in acral melanomas which have no CCND1 copy number alteration and low-level CCND1 copy number increase (P = 0.108). Cyclin D1 protein expression level correlated positively with CCND1 copy number in acral melanomas with high-level CCND1 copy number increase (P = 0.038). The sensitivity, specificity and positive predictive value of using cyclin D1 IHC to predict CCND1 FISH result was 72.4, 62.5 and 63.6%. Increase in CCND1 copy number was associated with Breslow thickness in invasive acral melanoma.ConclusionHigh-level increase in the CCND1 copy number can induce high cyclin D1 protein expression in acral melanomas. However low-level increase and normal CCND1 copy number have no obvious correlation with protein expression. Cyclin D1 IHC cannot serve as a surrogate for CCND1 FISH in acral melanomas.

Three-dimensional histological explanation of the dermoscopy patterns in acral melanocytic lesions.

Dermoscopic images of pigmented lesions have distinct features on the sole where skin ridges and furrows exist. Pigmentation of benign nevus usually locates on the skin furrow, while the malignant melanoma is pigmented on the skin ridge. Correspondence between dermoscopy and pathology in the pigmented lesions on soles have been studied based on conventional vertical pathological images. However, for the full understanding of the correspondence, observation of horizontal histological images would be required, because the epidermis constructs unique horizontal structures, namely crista profunda limitans, crista profunda intermedia, and transverse ridge. In this study, we analyzed basic dermoscopic images of the representative acral melanocytic lesions (nevus, lentigo, and malignant melanoma) by horizonal histological images. We created serial horizontal pathological images by digital reconstruction of a hundred of serial vertical images. We could show that parallel furrow pattern is created by the pigmentation of crista profunda limitans, parallel ridge pattern by the pigmentation of both of crista profunda limitans and crista profunda intermediate, and lattice-like pattern by the pigmentation of transverse ridge. Our results would be useful for the intuitive histological understanding of dermoscopy.

Acral subcorneal hematoma: Additional dermoscopic findings differentiating it from acral melanocytic lesions

Background: Acral subcorneal hematoma (ASH) is a dark-colored skin lesion of the palms and/or soles due to bleeding. ASH may be difficult to be clinically differentiated from acral melanocytic lesions, resulting in unnecessary biopsies. Few researches reported the importance of dermoscopy in differentiating ASH from acral melanocytic lesions. Purpose: This study aims at reporting the dermoscopic features in a series of ASH to facilitate precise diagnosis and to avoid performing unnecessary surgical techniques. Methods: Eighteen patients with ASH were studied. Dermoscopic images were obtained using a handheld dermoscope and a dermoscope-adopted phone camera. Paring test was performed on all lesions. Results: The preliminary diagnoses of the lesions were ASH in 55.6%, acral melanocytic nevi in 33.3%, and acral lentiginous melanoma in the remaining 11.1%. Dermoscopically, the lesion colors were red-black in 44.4%, black in 27.8%, and brown in the remaining 27.8%. The pigmentation patterns were homogeneous (structureless) in 55.6%, parallel ridge in 27.8%, and negative pseudonetwork in the remaining 16.6%. Over 44% of the lesions had red and/or brown globular satellites. Peripheral red lines with/without radial extensions were noticed around ASH in 55.6%. Paring led to complete removal of pigmentation in all ASH (100%), with the appearance of post-paring blood-tinged serum in 55.6%. No skin biopsies were performed. Conclusion: Although there is clinical similarity between ASH and acral melanocytic lesions, dermoscopy and paring test can facilitate a precise diagnosis and markedly decrease the need for unnecessary invasive procedures.

Acral melanocytic nevi in the Polish population: prevalence, clinical characteristics and dermoscopic patterns.

IntroductionAcral melanocytic nevi dermoscopic patterns have been well described in several populations. There have been no prospective studies assessing the prevalence, clinical characteristics and dermoscopic patterns of acral nevi in the Polish population.AimTo characterize the prevalence of acral nevi, frequency of dermoscopic patterns, relationships between acral nevi and patients’ characteristics.Material and methodsThis was a prospective study conducted in the Dermatological Outpatient Clinic of the University Hospital in Krakow. Study inclusion criteria: presence of nevi on foot soles and/or palms, Caucasian race, Polish origin, and age ≥ 18 years.ResultsSix hundred and twenty-four acral melanocytic lesions were observed in 287 patients, 174 (60.6%) women and 113 (39.4%) men, mean age 43.5 and 42.8 years, respectively. Four hundred and thirty-four (69.6%) lesions were present on soles, 190 (30.4%) on palms. No acral melanomas were detected. The following dermoscopic patterns were observed: parallel furrow 262 (42%), lattice-like 106 (17%), fibrillar 66 (11%) and other 190 (30%). Patients with acral nevi on the soles or both on the palms and soles had a higher number of atypical nevi on the body (p = 0.011) and a much higher total body nevi count (p = 0.043), when compared to those with acral nevi only on the palms.ConclusionsThe study revealed a higher prevalence of acral nevi in the analysed population. A higher number of acral nevi was associated with a higher number of atypical nevi and higher total body nevi count, the risk factors for melanoma. Because of that it is possible to note that a higher number of acral nevi should increase diagnostic alertness.

Region Adjacency Graph Approach for Acral Melanocytic Lesion Segmentation

Malignant melanoma is among the fastest increasing malignancies in many countries. Due to its propensity to metastasize and lack of effective therapies for most patients with advanced disease, early detection of melanoma is a clinical imperative. In non-Caucasian populations, melanomas are frequently located in acral volar areas and their dermoscopic appearance differs from the non-acral ones. Although lesion segmentation is a natural preliminary step towards its further analysis, so far virtually no acral skin lesion segmentation method has been proposed. Our goal was to develop an effective segmentation algorithm dedicated for acral lesions. We obtain a superpixel oversegmentation of a lesion image by performing clustering in a joint color-spatial 5d space defined by coordinates of CIELAB color space and spatial coordinates of the image. We then construct a region adjacency graph based on this superpixel representation. We obtain the ultimate segmentation result by performing a hierarchical region merging. The proposed segmentation method has been tested on 134 color dermoscopic images of different types of acral melanocytic lesions (including melanoma) from various sources. It achieved an average Dice index value of 0.85, accuracy 0.91, precision 0.89, sensitivity 0.87, and specificity 0.88. Experimental results suggest the effectiveness of the proposed method, which would help improve the accuracy of other diagnostic algorithms for acral melanoma detection. The results also suggest that the computational approach towards lesion segmentation yields more stable output than manual segmentation by dermatologists.

Educational and practice gaps in the management of volar melanocytic lesions.

The benign and malignant patterns of acral melanocytic naevi (AMN) and acral melanomas (AM) have been defined in a series of retrospective studies. A three-step algorithm was developed to determine when to biopsy acral melanocytic lesions. This algorithm has only been applied to a Japanese population. Our study aimed to review the current management strategy of acral melanocytic lesions and to investigate the utility of the three-step algorithm in a predominately Caucasian cohort. A retrospective search of the pathology and image databases at Mayo Clinic was performed between the years 2006 and 2016. Only cases located on a volar surface with dermoscopic images were included. Two dermatologists reviewed all dermoscopic images and assigned a global dermoscopic pattern. Clinical and follow-up data were gathered by chart review. All lesions with known diameter and pathological diagnosis were used for the three-step algorithm. Regular fibrillar and ridge patterns were more likely to be biopsied (P=0.01). The majority of AMN (58.1%) and AM (60%) biopsied were due to physician-deemed concerning dermoscopic patterns. 39.2% of these cases were parallel furrow, lattice-like or regular fibrillar. When patients were asked to follow-up within a 3- to 6-month period, only 16.7% of the patients returned within that interval. The three-step algorithm would have correctly identified four of five AM for biopsy, missing a 6mm, multicomponent, invasive melanoma. We found one major educational gap in the recognition of low-risk lesions with high rates of biopsy of the fibrillary pattern. Recognizing low-risk dermoscopic patterns could reduce the rate of biopsy of AMN by 23.3%. We identified two major practice gaps, poor patient compliance with follow-up and the potential insensitivity of the three-step algorithm to small multicomponent acral melanocytic lesions.

Genetic Alterations in Primary Acral Melanoma and Acral Melanocytic Nevus in Korea: Common Mutated Genes Show Distinct Cytomorphological Features

Acral melanoma occurring on the palms, soles, and nails is the most common subtype of cutaneous melanoma in Asians. Genetic alterations in acral melanoma and acral melanocytic nevus are not well known. We performed next-generation sequencing and evaluated the correlations between genetic information and the clinicopathologic characteristics from 85 Korean patients with acral melanocytic neoplasms. Of the 64 patients with acral melanoma, most had lesions at the T2 stage or higher, and the heel was the most common anatomical site of melanoma (n= 34 [53.1%]). The five most common mutations were BRAF (22 [34.4%]), NRAS (14, [21.9%]), NF1 (11, [17.2%]), GNAQ (12, [17.2%]), and KIT (7, [10.9%]). In the 21 acral melanocytic nevi, those five gene mutations were also common. Copy number variations were also frequently detected in 75% of acral melanomas and 47.6% of acral melanocytic nevi, and amplification was more common than deletion in both lesions. BRAF mutation was associated with round epithelioid cells and NRAS and NF1 mutations with bizarre cells. NF1 and GNAQ mutations showed elongated and spindle cells with prominent dendrites in acral melanomas. KIT mutations were common in amelanotic acral melanoma. This study suggests that common mutated genes are associated with distinct cytomorphological features in acral melanocytic lesions.

Improving the diagnosis and treatment of acral melanocytic lesions.

Melanocytic lesions of acral sites are common, with an estimated prevalence of 28-36% in the USA. While the majority of these lesions are benign, differentiation from acral melanoma (AM) is often challenging. AM is a unique subtype of melanoma, with distinct molecular characteristics that are thought to contribute to its high rate of locoregional recurrence and worse prognosis. The advent of dermoscopy has since improved the diagnostic accuracy of AM, resulting in earlier detection and arguably improved survival. Additionally, the identification of unique genomic amplifications in AM invites the potential for future AM-specific targeted therapies. Herein, we discuss the importance of dermoscopy in the diagnosis of acral melanocytic lesions and review the treatment strategies for AM.

Acral melanocytic lesions in the United States: Prevalence, awareness, and dermoscopic patterns in skin-of-color and non-Hispanic white patients

Acral lentiginous melanoma has increased mortality compared with other melanoma subtypes and disproportionately affects ethnic minorities. Acral melanocytic lesions have not been well studied in diverse populations of the United States. We sought to assess the prevalence, awareness, and dermoscopic patterns of acral melanocytic lesions in skin-of-color and non-Hispanic white patients. We prospectively examined the palms and soles of 1052 patients presenting to dermatology clinics in New York, NY, and Miami, FL, from October 2013 to April 2015. Acral melanocytic lesions were observed in 36% of our cohort. Skin-of-color patients were more likely to have acral melanocytic lesions than non-Hispanic white patients (P<.01). Acral melanocytic lesions correlated with increased mole counts, particularly on non-Hispanic white patients. The majority of lesions demonstrated benign dermoscopic patterns. We observed 2 lesions with the parallel ridge pattern in our cohort, both found to be atypical nevi on biopsy specimen. Patients often lacked awareness of the presence of their lesions. Interobserver variability in assessing dermoscopic patterns is a limitation. Melanocytic lesions of the palms and soles are common, particularly in a cohort of multiple ethnicities from the United States. Dermoscopy of acral lesions is an important clinical tool for diagnosis and management of these lesions.

Expression of soluble adenylyl cyclase in acral melanomas.

Soluble adenylyl cyclase (sAC) regulates melanocytic cells, and is a diagnostic marker for pigmented skin lesions. Because only a few studies on sAC expression in acral melanomas have been performed, we investigated the histopathological significance of sAC expression in 33 cases of acral melanoma, and assessed its diagnostic value in distinguishing melanoma insitu (MIS, n=17) from acral invasive melanomas (n=16) and melanocytic naevi (n=11). Acral melanomas exhibited more marked nuclear immunopositivity compared with acral melanocytic naevi. sAC expression significantly correlated with the nuclear morphology of melanocytes and melanoma cells, namely, hyperchromatic nuclei and prominent nucleoli within vesicular nuclei. sAC expression was predominantly observed in the hyperchromatic nuclei of MIS and the prominent nucleoli invasive melanomas, respectively. In vitro culture models of melanocytes and melanoma cell lines exhibited sAC staining patterns similar to those of acral melanomas. Differentiation induction showed that nuclear and nucleolar expression varied depending on cell morphology. sAC immunostaining may be useful for the differential diagnosis of acral melanocytic lesions, and sAC expressed in the nucleus and nucleolus might be related to cytological and nuclear changes associated with invasion and progression of acral melanomas.

Palmar and plantar melanomas differ for sex prevalence and tumor thickness but not for dermoscopic patterns

The specific anatomy of the glabrous skin, characterized by marked orthokeratosis and the presence of furrows and ridges, results in peculiar dermoscopic patterns of acral melanocytic lesions. Most frequently, acral nevi are typified by a parallel furrow pattern and acral melanoma (AM) by a parallel ridge pattern (PRP). Although the dermoscopic patterns of AM have been extensively investigated, little attention has been paid to site-related differences between palmar and plantar AM. The current study aimed to compare patients' characteristics, melanoma thickness, and the morphologic variability of AM depending on the localization on palms or soles. Patients demographics and dermoscopic images of 118 AM, including 99 (83.9%) plantar and 19 (16.1%) palmar lesions (mean thickness, 2.1 mm), were extracted from the databases of seven pigmented skin lesion clinics and were evaluated for the presence of predefined criteria. Palmar melanomas were remarkably more frequent in women (male-to-female ratio, 1/3.8) and thinner than plantar melanomas (1.3 vs. 2.2 mm). Dermoscopically, no significant differences were found between plantar and palmar melanomas, with PRP scored in 64.6 and 68.4% of plantar and palmar lesions, respectively. Non-site-specific melanoma criteria were detected in 83.9% of lesions and, among melanomas not exhibiting a PRP, 95.1% showed at least one non-site-specific melanoma criterion. In conclusion, plantar and palmar AMs show sex-related and thickness-related differences, but do not differ with respect to their dermoscopic features. For cases lacking the PRP, non-site-specific melanoma criteria may be considered as helpful additional clues for the correct diagnosis.

Recurrent acral lentiginous melanoma in situ suggesting the field cell theory.

Dear Editor: Acral lentiginous melanoma (ALM) is the most common type of cutaneous melanoma in Asians. Traditionally, ALM is believed to have a poor prognosis because of its aggressive behavior and a short radial growth phase, compared with that of lentigo maligna melanoma1. We describe a case of recurrent ALM in situ around the primary site during 8 years. A 56-year-old female patient presented with a black macule having an irregular border and color variegation on the left heel, which started 8 years ago (Fig. 1A). Dermoscopic examination showed a parallel ridge pattern and irregular pigmentation. She had undergone excisional biopsy (3-mm margin), which revealed only a few scattered melanocytes along the basal layer. She had returned after 2 years (Fig. 1B) and then after 4 years (Fig. 1C) because of newly appearing brown patches around the first location. Serial punch biopsies revealed mild melanocytic hyperplasia without marked cytologic atypia again. The results made a pathologist hesitant to diagnose ALM in situ instead of atypical melanocytic At that time, the patient didn't want additional surgery; we recommended regular follow-up considering the possibility of melanocytic proliferation. Most recently, she presented with further enlarged, multiple pigmented patches (Fig. 1D). She was treated with wide excision (1-cm margin) and split-thickness skin graft under the consideration of malignant melanoma. Bland lentiginous proliferation of melanocytes confined to the epidermis prompted the final diagnosis of ALM in situ (Fig. 1E). Immunohistochemically, melanocytes were stained positively for Melan-A, HMB-45, and anti-S-100 (Fig. 1F). Fig. 1 Acral lentiginous melanoma in situ. Clinical and histopathological feature. (A) Initial presentation 8 years ago. (B) Second presentation 6 years ago. (C) Third presentation 4 years ago. (D) Last presentation. Left, gross picture of the lesion; center, ... ALM was believed to have an aggressive biological behavior. However, in Asians, the specific population was reported inconsistent with the classical concept. After Nogita et al.2 described melanosis of the foot, acral melanocytic lesions have been described with histopathologically subtle melanocytic proliferation, despite clinically malignant melanoma3. These lesions did not show invasive behavior over a decade; though some of them reappeared around the primary site even after the surgical excision. There has been debate about the nature of these lesions; however, they are now considered as the precursor of ALM that fulfills both the clinical and dermoscopic criteria4. The most notable feature of our case was the recurrent melanocytic lesions appearing around the primary site in the absence of invasion during 8 years. Takata et al.5 suggested that acral and mucosal melanomas could originate from field melanocytes detected in normallooking skin extending over the obvious lesion. These field cells harbor mutations of the KIT gene and amplifications of cyclin D1 or cyclin-dependent kinase 4 gene. Although our case initially showed only bland melanocytic proliferation without marked atypia or invasion, local melanoma could reappear from the residual field cells. Therefore, we recommend that the clinician should consider these lesions as ALM in situ and treat with early complete excision. Also, it is better to perform an excisional biopsy for a review of the entire lesion in the suspicious acral melanocytic lesions. Finally, regular follow-up for several years is important for the detection of reappearing melanoma around the primary site, even after the surgical excision.

TERT and AURKA Gene Copy Number Gains Enhance the Detection of Acral Lentiginous Melanomas by Fluorescence in Situ Hybridization

The study of specific chromosomal loci through fluorescence in situ hybridization (FISH) is useful in differential diagnosis of melanocytic tumors. However, sensitivity rates vary, probably because of molecular heterogeneity. Acral lentiginous melanomas are characterized by copy number gains of small genomic regions, including CCND1, TERT, and AURKA. In a series of 58 acral melanocytic lesions, we explored the value of a four-color FISH probe, used in addition to determining MYC gene status, and assessed the potential diagnostic usefulness of newly developed probes targeting TERT and AURKA. Moreover, we tested CCND1, TERT, and AURKA protein expression by immunohistochemistry. The four-color FISH probe detected 85.3% of melanomas and 29.4% of TERT and AURKA copy number gains. Sensitivity was 97% (confidence interval 95%, 82.9% to 99.8%) for the combined results of all probes. No MYC copy number gains were detected. No nevi showed aberrations. Immunohistochemistry revealed a higher percentage of cells positive for CCND1, TERT, and AURKA protein in melanomas than in nevi (P ≤ 0.001). A significant correlation between gene copy number gain and protein expression was found for CCND1 (P = 0.015). Our results indicate that addition of specific FISH probes to the current probe could improve sensitivity for the diagnosis of acral melanomas. Further studies in larger numbers of cases are needed to validate these results.

Dermoscopic features of melanocytic lesions on volar skin: 178 case reports

Objective To investigate the dermoscopic features of palmoplantar melanocytic lesions.Methods The dermoscopic images of palmoplantar melanocytic lesions that underwent examination in the Department of Dermatology in Peking University First Hospital from September 2009 to October 2011,were retrospectively analyzed.Results Totally,155 benign acral melanocytic lesions in 121 patients and 23 acral melanomas in 22 patients were analysed in this study.Among the benign acral melanocytic lesions,the parallel furrow pattern and its variations (34.2％) were the most common,followed by the fibrillar pattern (22.6％).Two benign lesions (1.3％) showed a parallel ridge pattern.Of 23 melanoma lesions,12 (52.2％) exhibited parallel ridge pattern,and 14 (60.9％) showed irregular diffuse pigmentation that was present in all of the invasive melanoma lesions.The fibrillar pattern,as a common benign acral dermoscopic pattern,was also present in 39.1％ of melanoma specimens.Conclusions Dermoscopy is valuable to some extent in the differential diagnosis of benign melanocytic nevi and malignant melanoma in palmoplantar region,and may facilitate the secreening for early melanoma.

Videodermoscopic pattern analysis of acral melanocytic nevi

Three major and three minor types of acral melanocytic lesions have been described: parallel furrow, lattice-like, fibrillar, reticular, homogeneous and globular. To examine the dermoscopic patterns of acral melanocytic lesions and to investigate the association of these patterns with clinical features. This study included 419 acral melanocytic lesions of 295 patients. Dermoscopic images were stored in a standardized digital system and assessed. The incidence rates of the patterns were as follows: parallel furrow (62.5%), reticular (12.2%), globular (7.6%), fibrillar (5.0%), lattice-like (4.3%), homogeneous (3.8%), non-typical (3.8%), globulostreak-like (0.5%) and parallel ridge (0.2%). There was a significant association between pattern and diameter; nevi showing globular pattern were significantly smaller than those showing lattice-like pattern. There was a significant correlation between pattern and localization. The fibrillar pattern was observed more commonly on the feet, and the lattice-like pattern was seen almost entirely on the hands. Homogeneous and globular patterns were proportionately more common on the feet than on the hands. A significant association was found between patterns and colors. Compared with the lattice-like pattern, parallel furrow, fibrillar and homogeneous patterns were lighter in color; the globular pattern was darker than the homogeneous pattern. There was no significant correlations between pattern and clinical presentation. In conclusion, unlike all other studies, in the present study, the two most common patterns following the parallel furrow pattern were reticular and globular, which are minor patterns. Besides the differences in pattern distribution and inherent variability in individual assessment, the age of the study group and location of nevi influence the pattern, possibly in association with race.