Expression of LOXL3, NES, and SNAI1 in Melanoma Genesis and Progression.

Melanoma is the most severe type of skin cancer and among the most malignant neoplasms in humans. With the growing incidence of melanoma, increased numbers of therapeutic options, and the potential to target specific proteins, understanding the basic mechanisms underlying the disease's progression and resistance to treatment has never been more important. LOXL3, SNAI1, and NES are key factors in melanoma genesis, regulating tumor growth, metastasis, and cellular differentiation. In our study, we explored the potential role of LOXL3, SNAI1, and NES in melanoma progression and metastasis among patients with dysplastic nevi, melanoma in situ, and BRAF+ and BRAF- metastatic melanoma, using immunofluorescence and qPCR analysis. Our results reveal a significant increase in LOXL3 expression and the highest NES expression in BRAF+ melanoma compared to BRAF-, dysplastic nevi, and melanoma in situ. As for SNAI1, the highest expression was observed in the metastatic melanoma group, without significant differences among groups. We found co-expression of LOXL3 and SNAI1 in the perinuclear area of all investigated subgroups and NES and SNAI1 co-expression in melanoma cells. These findings suggest a codependence or collaboration between these markers in melanoma EMT, suggesting new potential therapeutic interventions to block the EMT cascade that could significantly affect survival in many melanoma patients.

Clinical implication of PRAME immunohistochemistry in differentiating melanoma in situ and dysplastic nevus in non-acral nevus-associated melanoma in situ: An institutional experience and meta-analysis.

INTRODUCTION: PReferentially expressed Antigen in MElanoma (PRAME) has shown utility in differentiating benign from malignant melanocytic neoplasms. In this study, we investigated the clinical significance of PRAME expression in dysplastic nevi (DN) and nevus-associated melanoma in situ (MIS). METHODS: We included 172 DN and 38 nevus-associated MIS from our institutional archive. PRAME positive expression was defined as nuclear staining in at least 75% of melanocytes. In addition, relevant studies from PubMed and Web of Science were incorporated into a meta-analysis using the random-effects model to assess PRAME expression in MIS and DN. RESULTS: Our institutional data revealed that 71.1% of nevus-associated MIS cases exhibited positive PRAME expression in the MIS components, whereas all DN components were negative for PRAME. 5.7% of cases diagnosed as DN in our cohort demonstrated diffuse positivity for PRAME. Notably, MIS associated with DN displaying epidermal and dermal components displayed a higher likelihood of PRAME positivity compared to those arising on a background of DN with solely epidermal (junctional) components (84% vs. 46%, p = 0.024). The meta-analysis indicated that the pooled PRAME positivity in MIS and DN was 54.5% and 1.9%, respectively. CONCLUSION: PRAME is a valuable immunohistochemical marker for differentiating MIS from DN, particularly in the context of nevus-associated MIS.

Nevi and Melanoma.

Cutaneous melanoma is an aggressive form of skin cancer derived from skin melanocytes and is associated with significant morbidity and mortality. A significant fraction of melanomas are associated with precursor lesions, benign clonal proliferations of melanocytes called nevi. Nevi can be either congenital or acquired later in life. Identical oncogenic driver mutations are found in benign nevi and melanoma. While much progress has been made in our understanding of nevus formation and the molecular steps required for transformation of nevi into melanoma, the clinical diagnosis of benign versus malignant lesions remains challenging.

Evaluation of MMP-9, MMP-13, MMP-21, and TIMP-1 expressions in malign melanom, dysplastic nevi, and banal nevi.

OBJECTIVE: Although the role of MMPs in the pathogenesis of melanoma is known, few studies have investigated their role in the development of nevi and dysplastic nevi. This study aims to search the expression differences of MMP-9, MMP-13, MMP-21, and TIMP-1 between malignant melanoma (MM), intradermal nevi (IDN), and dysplastic nevi (DN). METHODS: MMP-9, MMP-13, MMP-21, and TIMP-1 antibodies were studied immunohistochemically for 60 cases in our pathology clinic archive between 2013 and 2014. RESULTS: The MM group had the highest expression percentage and intensity for MMP-9 (p<0.001). There was no statistical significance between MMP-13 expression intensities of lesion cells and stromal cells and stromal expression intensities (p>0.05). MMP-21 lesion staining intensities in DN and MM compared to IDN were statistically significant (p=0.001, p=0.011, respectively). For TIMP-1, there was a significant difference between the IDN and the MM group regarding the staining proportion of lesion cells (p<0.01). There was a statistically significant difference in all groups according to lesion cells' expression intensity. (IDN-DN p<0.001, IDN-MM p=0.044, DN-MM p<0.001). CONCLUSION: The following markers can be helpful when lesions cannot be differentiated; increased staining proportions and intensity of MMP-9 in both lesion and stromal cells favor MM in cases where MM and IDN cannot be differentiated. The increased MMP-13 staining proportion of lesion cells can favor DN in cases where the pathologist cannot differentiate DN and MM. Intense expression of MMP-21 by lesion cells can be a potential marker for evaluating the lesion in favor of DN in cases where DN and IDN cannot be differentiated. The high expression intensity of TIMP-1 in lesion cells can favor DN in cases where there is ambiguity between DN and MM. High expression proportion and intensity of stromal cells of TIMP-1 can be useable in favor of MM in cases where MM and DN cannot be differentiated.

Encuesta sobre el manejo del nevus displásico por los dermatólogos de la sección Centro de la Academia Española de Dermatología y Venereología (AEDV) / Survey on the Management of Dysplastic Nevus by Dermatologists in the Center-Spain section of the Spanish Academy of Dermatology and Venereology (AEDV)

Antecedentes y objetivos No existen guías clínicas para el manejo del nevus displásico (ND). Determinaremos el porcentaje de dermatólogos de la sección Centro de la Academia Española de Dermatología y Venereología (AEDV) que ampliarían márgenes o tendrían actitud conservadora en un ND, y si los antecedentes personales (AP) y/o familiares (AF) de melanoma modificarían la actitud tomada frente a un paciente sin antecedentes de interés. Material y métodos Se difundió la encuesta a 738 dermatólogos y se recogieron datos de forma anónima del 15 de junio de 2022 al 31 de julio de 2022. Las variables de exposición fueron el grado de displasia (bajo/alto), los márgenes (afecto/libre) y los antecedentes de melanoma (sin antecedentes/AF/AP). Las variables dependientes (actitud) incluyeron observación/márgenes de 1-4mm /márgenes 5-10mm. Resultados Se recibieron 86 respuestas. Si el patólogo informase bordes afectos en un ND de bajo grado, el 60,5% ampliarían márgenes de 1 a 4mm, mientras que si los márgenes están libres el 97,7%, tendrían una actitud conservadora. Si el patólogo informara bordes afectos en un ND de alto grado, solo el 1,2% tendrían una actitud conservadora, porcentaje que se incrementa notablemente si los márgenes están libres (68,6%). El AF o el AP de melanoma no influirían en la actitud de la mayoría. Conclusiones El manejo del ND no es uniforme entre los dermatólogos de la sección centro de la AEDV, especialmente en el caso de ND de bajo grado con bordes afectos y ND de alto grado con bordes libres. El AF o el AP de melanoma no modifican en la mayor parte de los casos la actitud clínica (AU)

Background and objectives There are no clinical guidelines on the management of dysplastic nevus (DN). The aims of this study were to determine the percentage of dermatologists in the center-Spain section of the Spanish Academy of Dermatology and Venereology (AEDV) who would manage a histologically confirmed DN with a watch-and-wait approach or with wider surgical margins and to investigate whether their attitudes would vary depending on whether or not the patient had a personal and/or family history of melanoma. Material and methods We collected data from an anonymous survey sent to 738 dermatologists between June 15 and July 31, 2022. The independent variables were degree of dysplasia (low vs. high), margin status (positive vs. negative), and a personal or family history of melanoma (yes vs. no in both cases). The dependent variables were attitude towards management (watch-and-wait vs. re-excision with a surgical margin of 1 to 4mm or re-excision with a surgical margin of 5 to 10mm). Results We obtained 86 responses to the questionnaire. When pathology indicated a low-grade DN, 60.5% of dermatologists stated they would obtain a surgical margin of 1 to 4mm if the first margins were positive, and 97.7% would watch and wait if the report described negative margins. For high-grade DNs, 1.2% of dermatologists would watch and wait to manage DN with positive margins; 68.8% would use this approach for negative margins. A family or personal history of melanoma had no influence on most of the dermatologists’ attitudes. Conclusions Management strategies for DN among dermatologists from the center-Spain section of the AEDV varied, particularly when faced with low-grade DN with positive margins and high-grade DN with negative margins. A family or personal history of melanoma did not influence clinical attitudes in most cases (AU)

[Translated article] Survey on the Management of Dysplastic Nevus by Dermatologists in the Center-Spain Section of the Spanish Academy of Dermatology and Venereology (AEDV) / Encuesta sobre el manejo del nevus displásico por los dermatólogos de la sección Centro de la Academia Española de Dermatología y Venereología (AEDV)

Background and objectives There are no clinical guidelines on the management of dysplastic nevus (DN). The aims of this study were to determine the percentage of dermatologists in the center-Spain section of the Spanish Academy of Dermatology and Venereology (AEDV) who would manage a histologically confirmed DN with a watch-and-wait approach or with wider surgical margins and to investigate whether their attitudes would vary depending on whether or not the patient had a personal and/or family history of melanoma. Material and methods We collected data from an anonymous survey sent to 738 dermatologists between June 15 and July 31, 2022. The independent variables were degree of dysplasia (low vs. high), margin status (positive vs. negative), and a personal or family history of melanoma (yes vs. no in both cases). The dependent variables were attitude towards management (watch-and-wait vs. re-excision with a surgical margin of 1 to 4mm or re-excision with a surgical margin of 5 to 10mm). Results We obtained 86 responses to the questionnaire. When pathology indicated a low-grade DN, 60.5% of dermatologists stated they would obtain a surgical margin of 1 to 4mm if the first margins were positive, and 97.7% would watch and wait if the report described negative margins. For high-grade DNs, 1.2% of dermatologists would watch and wait to manage DN with positive margins; 68.8% would use this approach for negative margins. A family or personal history of melanoma had no influence on most of the dermatologists’ attitudes. Conclusions Management strategies for DN among dermatologists from the center-Spain section of the AEDV varied, particularly when faced with low-grade DN with positive margins and high-grade DN with negative margins. A family or personal history of melanoma did not influence clinical attitudes in most cases (AU)

Antecedentes y objetivos No existen guías clínicas para el manejo del nevus displásico (ND). Determinaremos el porcentaje de dermatólogos de la sección Centro de la Academia Española de Dermatología y Venereología (AEDV) que ampliarían márgenes o tendrían actitud conservadora en un ND, y si los antecedentes personales (AP) y/o familiares (AF) de melanoma modificarían la actitud tomada frente a un paciente sin antecedentes de interés. Material y métodos Se difundió la encuesta a 738 dermatólogos y se recogieron datos de forma anónima del 15 de junio de 2022 al 31 de julio de 2022. Las variables de exposición fueron el grado de displasia (bajo/alto), los márgenes (afecto/libre) y los antecedentes de melanoma (sin antecedentes/AF/AP). Las variables dependientes (actitud) incluyeron observación/márgenes de 1-4mm /márgenes 5-10mm. Resultados Se recibieron 86 respuestas. Si el patólogo informase bordes afectos en un ND de bajo grado, el 60,5% ampliarían márgenes de 1 a 4mm, mientras que si los márgenes están libres el 97,7%, tendrían una actitud conservadora. Si el patólogo informara bordes afectos en un ND de alto grado, solo el 1,2% tendrían una actitud conservadora, porcentaje que se incrementa notablemente si los márgenes están libres (68,6%). El AF o el AP de melanoma no influirían en la actitud de la mayoría. Conclusiones El manejo del ND no es uniforme entre los dermatólogos de la sección centro de la AEDV, especialmente en el caso de ND de bajo grado con bordes afectos y ND de alto grado con bordes libres. El AF o el AP de melanoma no modifican en la mayor parte de los casos la actitud clínica (AU)

Multiple Primary Melanoma: A Five-Year Prospective Single-Center Follow-Up Study of Two MC1R R/R Genotype Carriers.

BACKGROUND: Multiple primary melanoma (MPM) is a diagnostic challenge even with ancillary imaging technologies available to dermatologists. In selected patients' phenotypes, the use of imaging approaches can help better understand lesion characteristics, and aid in early diagnosis and management. METHODS: Under a 5-year prospective single-center follow-up, 58 s primary melanomas (SPMs) were diagnosed in two first-degree relatives, with fair skin color, red hair, green eyes, and personal history of one previous melanoma each. Patients' behavior and descriptive demographic data were collected from medical records. The information on the first two primary melanomas (PMs) were retrieved from pathology reports. The characteristics of 60 melanomas were collected from medical records, video dermoscopy software, and pathology reports. Reflectance confocal microscopy (RCM) was performed prior to excision of 22 randomly selected melanomas. RESULTS: From February 2018 to May 2023, two patients underwent a pooled total of 214 excisional biopsies of suspect lesions, resulting in a combined benign versus malignant treatment ratio (NNT) of 2.0:1.0. The number of moles excised for each melanoma diagnosed (NNE) was 1.7:1.0 and 6.9:1.0 for the female and male patient respectively. The in-situ melanoma/invasive melanoma ratio (IIR) demonstrated a higher proportion of in-situ melanomas for both patients. From June 2018 to May 2023, a total of 58 SPMs were detected by the combination of total body skin exam (TBSE), total body skin photography (TBSP), digital dermoscopy (DD), and sequential digital dermoscopy imaging (SDDI) via comparative approach. The younger patient had her PM one month prior to the second and third cutaneous melanomas (CMs), characterizing a case of synchronous primary CM. The male older relative had a total of 7 nonsynchronous melanomas. CONCLUSIONS: This CM cohort is composed of 83.3% in-situ melanoma and 16.7% invasive melanoma. Both patients had a higher percentage of SPM with clinical nevus-like morphology (84.5%), global dermoscopic pattern of asymmetric multiple component (60.3%) and located on the lower limbs (46.6%). When RCM was performed prior to excision, 81% of SPM had features suggestive of malignancy. As well, invasive melanomas were more frequent in the lower limbs (40%). In the multivariate model, for the two high-risk patients studied, the chance of a not associated with nevus ("de novo") invasive SPM diagnosis is 25 times greater than the chance of a diagnosis of a nevus-associated invasive SPM.

Standardized Computer-Assisted Analysis of 5-hmC Immunoreactivity in Dysplastic Nevi and Superficial Spreading Melanomas.

5-Hydroxymethylcytosine (5-hmC) is an important intermediate of DNA demethylation. Hypomethylation of DNA is frequent in cancer, resulting in deregulation of 5-hmC levels in melanoma. However, the interpretation of the intensity and distribution of 5-hmC immunoreactivity is not very standardized, which makes its interpretation difficult. In this study, 5-hmC-stained histological slides of superficial spreading melanomas (SSM) and dysplastic compound nevi (DN) were digitized and analyzed using the digital pathology and image platform QuPath. Receiver operating characteristic/area under the curve (ROCAUC) and t-tests were performed. A p-value of <0.05 was used for statistical significance, and a ROCAUC score of >0.8 was considered a "good" result. In total, 92 5-hmC-stained specimens were analyzed, including 42 SSM (45.7%) and 50 DN (54.3%). The mean of 5-hmC-positive cells/mm2 for the epidermis and dermo-epidermal junction and the entire lesion differed significantly between DN and SSM (p = 0.002 and p = 0.006, respectively) and showed a trend towards higher immunoreactivity in the dermal component (p = 0.069). The ROCAUC of 5-hmC-positive cells of the epidermis and dermo-epidermal junction was 0.79, for the dermis 0.74, and for the entire lesion 0.76. These results show that the assessment of the epidermal with junctional expression of 5-hmC is slightly superior to dermal immunoreactivity in distinguishing between DN and SSM.

Survey on the Management of Dysplastic Nevus by Dermatologists in the Center-Spain section of the Spanish Academy of Dermatology and Venereology (AEDV). / Encuesta sobre el manejo del nevus displásico por los dermatólogos de la sección Centro de la Academia Española de Dermatología y Venereología (AEDV).

BACKGROUND AND OBJECTIVES: There are no clinical guidelines on the management of dysplastic nevus (DN). The aims of this study were to determine the percentage of dermatologists in the center-Spain section of the Spanish Academy of Dermatology and Venereology (AEDV) who would manage a histologically confirmed DN with a watch-and-wait approach or with wider surgical margins and to investigate whether their attitudes would vary depending on whether or not the patient had a personal and/or family history of melanoma. MATERIAL AND METHODS: We collected data from an anonymous survey sent to 738 dermatologists between June 15 and July 31, 2022. The independent variables were degree of dysplasia (low vs. high), margin status (positive vs. negative), and a personal or family history of melanoma (yes vs. no in both cases). The dependent variables were attitude towards management (watch-and-wait vs. re-excision with a surgical margin of 1 to 4mm or re-excision with a surgical margin of 5 to 10mm). RESULTS: We obtained 86 responses to the questionnaire. When pathology indicated a low-grade DN, 60.5% of dermatologists stated they would obtain a surgical margin of 1 to 4mm if the first margins were positive, and 97.7% would watch and wait if the report described negative margins. For high-grade DNs, 1.2% of dermatologists would watch and wait to manage DN with positive margins; 68.8% would use this approach for negative margins. A family or personal history of melanoma had no influence on most of the dermatologists' attitudes. CONCLUSIONS: Management strategies for DN among dermatologists from the center-Spain section of the AEDV varied, particularly when faced with low-grade DN with positive margins and high-grade DN with negative margins. A family or personal history of melanoma did not influence clinical attitudes in most cases.

Optical coherence tomography confirms non-malignant pigmented lesions in phacomatosis pigmentokeratotica using a support vector machine learning algorithm.

INTRODUCTION: Phacomatosis pigmentokeratotica (PPK), an epidermal nevus syndrome, is characterized by the coexistence of nevus spilus and nevus sebaceus. Within the nevus spilus, an extensive range of atypical nevi of different morphologies may manifest. Pigmented lesions may fulfill the ABCDE criteria for melanoma, which may prompt a physician to perform a full-thickness biopsy. MOTIVATION: Excisions result in pain, mental distress, and physical disfigurement. For patients with a significant number of nevi with morphologic atypia, it may not be physically feasible to biopsy a large number of lesions. Optical coherence tomography (OCT) is a non-invasive imaging modality that may be used to visualize non-melanoma and melanoma skin cancers. MATERIALS AND METHOD: In this study, we used OCT to image pigmented lesions with morphologic atypia in a patient with PPK and assessed their quantitative optical properties compared to OCT cases of melanoma. We implement a support vector machine learning algorithm with Gabor wavelet transformation algorithm during post-image processing to extract optical properties and calculate attenuation coefficients. RESULTS: The algorithm was trained and tested to extract and classify textural data. CONCLUSION: We conclude that implementing this post-imaging machine learning algorithm to OCT images of pigmented lesions in PPK has been able to successfully confirm benign optical properties. Additionally, we identified remarkable differences in attenuation coefficient values and tissue optical characteristics, further defining separating benign features of pigmented lesions in PPK from malignant features.

Standardized Computer-Assisted Analysis of PRAME Immunoreactivity in Dysplastic Nevi and Superficial Spreading Melanomas.

PRAME (PReferentially expressed Antigen in MElanoma) is a cancer testis antigen that is frequently expressed in melanoma compared to benign melanocytic proliferations and nevi. However, the interpretation of the intensity and distribution of PRAME immunostaining is not standardized a lot, which makes interpretation difficult. PRAME-stained histological slides of superficial spreading melanomas (SSM) and dysplastic nevi (DN) were digitized and analyzed using the digital pathology and image platform QuPath. t-tests and ROC AUCs were performed with SPSS. A p-value of <0.05 was used for statistical significance, and a ROC AUC score of >0.8 was considered a good result. A cut-off score was defined in an evaluation cohort and subsequently analyzed in an independent validation cohort. In total, 81 PRAME-stained specimens were included. The evaluation cohort included 32 (50%) SSM and 32 (50%) DN, and the mean of PRAME-positive cells/mm2 for the entire lesion was 455.3 (SD 428.2) in SSM and 60.5 (SD 130.1; p < 0.001) in DN. The ROC AUC of PRAME-positive cells of the entire lesion was 0.866, and in the epidermis it was 0.901. The defined cut-off score to distinguish between DN and SSM was 97.67 cells/mm2. In the validation cohort, 16 out of 17 cases (94.1%) were correctly classified by the cut-off score. The computer-aided assessment of PRAME immunostaining is a useful tool in dermatopathology to distinguish between DN and SSM. Lesions with a moderate expression and indifferent morphologic features will remain a challenge for dermatopathologists.

Factors associated with suspected nonmelanoma skin cancers, dysplastic nevus, and cutaneous melanoma among first-time SpotMe screening program participants during 2009-2010.

BACKGROUND: There have been no studies of the American Academy of Dermatology's SpotMe skin cancer screening program to collectively analyze and determine the factors associated with suspected basal cell carcinoma (BCC), squamous cell carcinoma (SCC), dysplastic nevus (DN), and cutaneous melanoma (CM) diagnoses. OBJECTIVE: Describe the demographics, risk factors, and access to care profiles associated with suspected diagnoses of BCC, SCC, DN, and CM among first-time SpotMe screenees during 2009-2010. METHODS: We conducted a cross-sectional analysis of data from the SpotMe skin cancer screenings conducted in 2009 and 2010. We performed multivariable logistic regression analysis for each diagnosis, incorporating standard demographic, access to care, and risk factor variables in the models. RESULTS: Men, those without a regular dermatologist, persons reporting recently changing moles, and those with a personal history of melanoma were at increased risk for each of the suspected diagnoses analyzed. Uninsured persons were at increased risk for suspected malignancies (BCC, SCC, and CM). LIMITATIONS: Lack of histologic confirmation for diagnoses and cross-sectional design. CONCLUSION: Among first-time SpotMe participants, suspected diagnoses of BCC, SCC, DN, and CM shared several associated factors, which may be considered when planning outreach and screening for populations at risk for skin cancer.

Differences in nomenclature usage and preference among dermatopathologists for "dysplastic" nevi: A national survey.

BACKGROUND: Ongoing controversy exists regarding terminology used to describe atypical melanocytic nevi. Efforts to standardize nomenclature, including the 1992 NIH consensus conference, have been largely unsuccessful. Significant advances have revealed an increasingly detailed genetic picture of melanocytic neoplasms, including strong evidence for the existence of those with "intermediate" behavior. METHODS: We sent an electronic survey to dermatopathologists (n = 846) to assess trends in nomenclature usage and attitudes toward developing new consensus nomenclature for atypical melanocytic nevi. RESULTS: There were 229 complete responses (27.1% response rate). The most used/preferred nomenclature was "dysplastic nevus" (43%/39%, respectively), followed by the NIH-recommended terminology (28%/26%). Three-tier grading systems were most heavily used/preferred (79%/63%). Dermatopathologists based in New England were most likely to use the NIH terminology; on the other hand, "dysplastic nevus" or "other" were most used elsewhere (p = 0.029). Most (76%) expressed at least "moderate" enthusiasm for developing consensus nomenclature, with 47% "very" or "extremely" enthusiastic. CONCLUSION: Little has changed with the wide variation in terminology for atypical melanocytic nevi. There continues to be no one dominant terminology in use. However, there is enthusiasm for standardization. A new attempt at updated consensus nomenclature may be fruitful.

Dysplastic nevus part II: Dysplastic nevi: Molecular/genetic profiles and management.

Dermatologists frequently see patients with clinically atypical nevi and dermatopathologists interpret histologically dysplastic nevi on a near-daily basis, but there is great variability in the definition and management of such lesions. This part of the CME review focuses on information published since the previous comprehensive review (2012), with emphasis on molecular and genetic attributes of histologically dysplastic nevi and clinical management.

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.

Fractal Dimension Analysis of Melanocytic Nevi and Melanomas in Normal and Polarized Light-A Preliminary Report.

Clinical diagnosis of pigmented lesions can be a challenge in everyday practice. Benign and dysplastic nevi and melanomas may have similar clinical presentations, but completely different prognoses. Fractal dimensions of shape and texture can describe the complexity of the pigmented lesion structure. This study aims to apply fractal dimension analysis to differentiate melanomas, dysplastic nevi, and benign nevi in polarized and non-polarized light. A total of 87 Eighty-four patients with 97 lesions were included in this study. All examined lesions were photographed under polarized and non-polarized light, surgically removed, and examined by a histopathologist to establish the correct diagnosis. The obtained images were then processed and analyzed. Area, perimeter, and fractal dimensions of shape and texture were calculated for all the lesions under polarized and non-polarized light. The fractal dimension of shape in polarized light enables differentiating melanomas, dysplastic nevi, and benign nevi. It also makes it possible to distinguish melanomas from benign and dysplastic nevi under non-polarized light. The fractal dimension of texture allows distinguishing melanomas from benign and dysplastic nevi under polarized light. All examined parameters of shape and texture can be used for developing an automatic computer-aided diagnosis system. Polarized light is superior to non-polarized light for imaging texture details.

Texture Analysis in Diagnosing Skin Pigmented Lesions in Normal and Polarized Light-A Preliminary Report.

The differential diagnosis of benign nevi (BN), dysplastic nevi (DN), and melanomas (MM) represents a considerable clinical problem. These lesions are similar in clinical examination but have different prognoses and therapeutic management techniques. A texture analysis (TA) is a mathematical and statistical analysis of pixel patterns of a digital image. This study aims to demonstrate the relationship between the TA of digital images of pigmented lesions under polarized and non-polarized light and their histopathological diagnosis. Ninety pigmented lesions of 76 patients were included in this study. We obtained 166 regions of interest (ROI) images for MM, 166 for DN, and 166 for BN. The pictures were taken under polarized and non-polarized light. Selected image texture features (entropy and difference entropy and long-run emphasis) of ROIs were calculated. Those three equations were used to construct the texture index (TI) and bone index (BI). All of the presented features distinguish melanomas, benign and dysplastic lesions under polarized light very well. In non-polarized images, only the long-run emphasis moment and both indices effectively differentiated nevi from melanomas. TA is an objective method of assessing pigmented lesions and can be used in automatic diagnostic systems.

Dysplastic nevi and melanoma: microRNAs tell a divergent story.

BACKGROUND: dysplastic nevi (DN) share some clinical and histological features with melanoma and have been considered intermediate lesions toward malignant transformation. However, scientific evidence of DN representing melanoma precursors is still incomplete, and many observations pointed toward their being a distinct biological entity. The current definition of DN is also confusing and the practical consequence of this uncertainty is the excessive excision of DN with severe atypia. MicroRNAs (miRNAs) are small RNAs that regulate gene expression and whose global expression can classify normal and pathological tissues. OBJECTIVES: given these considerations, we decided to perform a small RNA profiling study in a group of DN and invasive melanomas obtained from the same patient, to assess tumor evolution according to the global microRNA expression. METHODS: we performed a small-RNA sequencing of 6 DN, 2 congenital nevi and 4 cutaneous melanomas obtained from 4 subjects and evaluated the global miRNA expression correlation between samples. RESULTS AND CONCLUSIONS: the hierarchical clustering and principal component analyses of global miRNA expression, independently grouped together DN and their matching congenital nevi and showed a divergence of DN miRNA profile from melanoma. Our study suggests that DN have a peculiar and different miRNA expression profile compared to melanomas developed in the same patient, thus supporting the hypothesis that DN are distinct biological entities and not melanoma precursors.