Recent advancements in the diagnosis and treatment of acral melanoma. / è‚¢ç«¯é»‘è‰²ç´ ç˜¤çš„è¯Šæ–­å’Œæ²»ç–—è¿›å±•.

Acral melanoma (AM) is the most common histologic subtype of melanoma in dark-skinned patients and is associated with a worse prognosis and a high mortality rate, largely due to the inconspicuous nature of early-stage lesions, which can lead to late diagnosis. Because of the overlapping clinical and histopathological features of AM with other forms of cutaneous melanomas, early detection of AM requires a multidisciplinary approach that integrates various diagnostic modalities, including clinical examination, dermoscopy, histopathology, molecular testing, radiological imaging, and blood tests. While surgery is the preferred method of treatment for AM, other therapeutic options may be employed based on the stage and underlying etiology of the disease. Immune checkpoint inhibitors, molecular targeted therapy, radiotherapy, chemotherapy, and oncolytic virotherapy represent promising advanced treatment options for AM. In this review, we provide an overview of the latest advancements in diagnostic and therapeutic methods for AM, highlighting the importance of early detection and the prompt, individualized management of this challenging disease.

Recognizing Histopathological Simulators of Melanoma to Avoid Misdiagnosis.

Melanocytic lesions have a wide morphological spectrum, ranging from benign nevi to malignant melanoma. In contrast to a diagnosis of a benign nevus, a diagnosis of melanoma could mean intensive treatment, lifetime monitoring, and a worse prognosis. Therefore, melanocytic tumors are notoriously challenging and associated with a high risk of litigation in surgical pathology. After describing the basic features of nevi and melanoma, this article describes the detailed clinical and histological features of those lesions that share many similar features with melanoma. The entities included are Spitz nevi and atypical Spitz tumors (AST), Reed nevus, dysplastic nevus, cellular blue nevus (CBN), deep penetrating nevus, combined nevus, recurrent nevus, irritated nevus, congenital pattern nevus, acral nevus, and nevi of special sites. Knowledge of these imitators can help pathologists distinguish between benign and malignant cases and avoid misdiagnosis.

Dermoscopic characteristics of acral melanocytic nevi in children and adolescents.

BACKGROUND/OBJECTIVE: There are limited data on the dermoscopic characteristics of acral nevi in the population under 18 years old. Our aim was to determine the frequency of acral volar nevi in children and adolescents, characterize their dermoscopic patterns, and identify relationships with age and location. METHODS: We prospectively examined the palms and soles of 1319 patients presenting to our outpatient clinic from July 2018 to April 2019. RESULTS: Acral volar nevi were observed in 28% of the children and adolescent population included in the study. A total of 474 nevi from 365 patients were examined. The presence of nevi increased with age. The most common dermoscopic pattern was parallel pigmented furrows, detected in 57.8% of nevi. The other patterns observed were combination (14.1%), fibrillar (10.1%), and latticelike (8.8%). The parallel furrow and globulostreak-like patterns were more common on the palms, whereas the fibrillar and combination patterns were more frequently seen on the plantar surfaces. While the frequency of the parallel pigmented furrow pattern did not differ between the 0- to 12-year and 13- to 18-year age-groups, the dotted variants of the parallel furrow were observed more frequently in the 0- to 12-year-olds (58.2%) than in the 13- to 18-year-olds (41.7%). A combination pattern and its most common variant, parallel furrow + crista dotted pattern, were detected at a significantly higher rate in the 0- to 12-year group (22.1% and 16.3%, respectively) compared to the 13- to 18-year group (11.4% and 6%, respectively). CONCLUSIONS: Acral melanocytic nevi are common in children and adolescents, and their dermoscopic patterns may be associated with anatomic localization and age.

Juvenile melanocytic acral nevus: A comparative study between MANIAC and non-MANIAC nevus and its clinicopathological characteristics.

BACKGROUND: Melanocytic acral nevi have a series of distinguishing features, including their location, patient age at onset, clinical progression, and histological findings. In particular, histopathological analysis often reveals a melanocytic acral nevus with intraepidermal ascent of cells (MANIAC nevus), which in some cases can be mistaken for atypia or malignancy. AIM: This study describes the clinicopathological characteristics of acral nevi in patients under 18 years old and contrasts the clinical and histological features between MANIAC vs non-MANIAC nevi. METHODS: This was a retrospective observational study, performed in our department in the decade between January 2007 and January 2017. We included patients younger than 18 years of age who were subjected to the removal of melanocytic acral nevi. RESULTS: A total of 70 patients were studied. 54.2% (38/70) were females and 45.8% (32/70) were males. With regard to the type of nevus, 34 were compound, 27 were junctional, and 9 were predominantly intradermal lesions. We identified a total of 41 MANIAC nevi and 29 non-MANIAC nevi. Statistically significant differences between these two groups were identified in nevus size (larger in MANIAC) and the frequency of compound nevi (higher in the MANIAC group), but not in the remainder of the histological parameters studied.

Depletion of primary cilium in acral melanoma.

BACKGROUND: A eukaryotic cell's primary cilium (PC) is critical for cell signaling, migration and homeostasis. Primary cilium dysfunction has been demonstrated in several malignancies, but whether primary cilia loss occurs in acral melanoma has remained unknown. To address this, we examined the ciliation index (% melanocytes containing a PC) of patient-derived, biopsy-proven acral melanoma and compared these to benign acral nevi. METHODS: We generated a pilot initiative study that included six acral melanomas and seven acral nevi derived from the foot. Using fluorescent immunohistochemistry, we calculated ciliation indexes of Sox10+ melanocytes. RESULTS: Average ciliation index for acral nevi was 74.0% (SE of the mean [SEM] 3.3%) vs 9.3% for acral melanoma (SEM 5.7%), finding a statistically significant difference between the groups (P-value <.001, two tailed t test). CONCLUSION: The data show a significant loss of primary cilia in malignant acral melanoma vs benign acral nevi, suggesting that cilia may play an important role during acral melanoma formation. Our data, which should be validated by a larger study with longer follow-up period, suggest that examining ciliation index may be a useful diagnostic test when distinguishing benign acral nevi from melanoma.

Age and Anatomical Location-Related Dermoscopic Patterns of 210 Acral Melanocytic Nevi in a Turkish Population.

BACKGROUND: Dermoscopy is a useful tool for earlier diagnosis and differentiating benign lesions from melanoma. OBJECTIVES: We aim to investigate dermoscopic features of acral nevi, age, and localisation-related findings of these lesions. METHODS: This was an observational, descriptive study. Patients were retrospectively collected from the Department of Dermatology. The patients with acral nevi were included in the study. Inclusion criteria were Turkish nationality and the presence of at least 1 acral nevus diagnosed both clinically and dermoscopically. Lesions in dorsal and subungual areas were excluded. All nevi were examined by the same dermatologist. RESULTS: The most common dermoscopic patterns were as follows: parallel furrow (87 patients; 41.4%), globular (24 patients; 11.4%), fibrillar (22 patients; 10.5%), combination patterns (19 patients; 9.1%), globulostreak-like (16 patients; 7.6%), lattice-like (15 patients; 7.1%), homogeneous (12 patients; 5.7%), nontypical (8 patients; 3.8%), parallel ridge (4 patients; 1.9%), reticular (2 patients; 1.0%), and crista dotted pattern (1 patient; 0.5%). The parallel furrow pattern was the most common pattern in all localisations. The number of parallel furrow patterns (5 lesions) was equal to the globulostreak-like pattern (5 lesions) on the thenar area. The number of parallel furrow patterns (4 lesions) was equal to the fibrillar pattern (4 lesions) on the heel. Parallel furrow (dotted variants) (11 lesions) and globulostreak-like patterns (5 lesions) were the most common patterns in the pediatric population (0-15 years old). The fibrillar pattern showed a tendency for soles (12 lesions), while a lattice-like pattern was seen more often in the plantar arch (3 lesions). CONCLUSIONS: Description of the dermoscopic features of acral nevi is important to improve management and reduce the number of unnecessary excisions. The most common patterns were parallel furrow, globular, and fibrillar in our study. Parallel furrow (dotted variants) and globulostreak-like patterns were the most common patterns in the pediatric population. The fibrillar pattern showed a tendency for soles, while a lattice-like pattern was seen more often on the plantar arch. Therefore, there may be a relation between anatomic localisation, age, and dermoscopic pattern.