Search results for "Nevus"
showing 10 items of 64 documents
The Amount of Melanin Influences p16 Loss in Spitzoid Melanocytic Lesions: Correlation With CDKN2A Status by FISH and MLPA.
2019
AIMS The risk assessment of spitzoid lesions is one of the most difficult challenges in dermatopathology practice. In this regard, the loss of p16 expression and the homozygous deletion of CDKN2A, have been pointed in the literature as reliable indicators of high risk. However, these findings are poorly reproducible, and the molecular bases underlying the loss of p16 expression remain unclear. We aimed to identify the underlying events causing loss of CDKN2A/p16 in spitzoid tumors. MATERIALS AND METHODS We evaluated the immunohistochemical expression of p16, and the presence of CDKN2A genetic alterations detected through fluorescence in situ hybridization (FISH) and multiplex ligation-depen…
Melanoma-Nevus Discrimination Based on Image Statistics in Few Spectral Channels
2016
The purpose of this paper is to offer a method for discrimination of cutaneous melanoma from benign nevus, founded on analysis of skin lesion image. At the core of method is calculation of mean and standard deviation of pixel optical density values for a few narrow spectral bands. Calculated values are compared with discriminating thresholds derived from a set of images of benign nevi and melanomas with known diagnosis. Classification is done applying weighted majority rule to results of thresholding. Verification against the available multispectral images of 32 melanomas and 94 benign nevi has shown that the method using three spectral bands provided zero false negative and four false posi…
Mosaic-activating FGFR2 mutation in two fetuses with papillomatous pedunculated sebaceous naevus
2016
International audience; Papillomatous pedunculated sebaceous naevus (PPSN) has been described as a subtype of sebaceous naevus (SN), typically affecting the scalp and face. In contrast with Schimmelpenning syndrome, no cerebral, ocular or skeletal anomalies have hitherto been reported. We report two unrelated fetuses with PPSN, one with large pink exophytic tumours, the other with minor features but similar microscopic findings. We performed whole-exome sequencing in affected skin tissue from fetus 1, which identified a postzygotic de novo FGFR2 c.1144T>C (p.Cys382Arg) mutation in 34[middle dot]6% of reads which was absent in the parents' blood. Targeted deep sequencing of FGFR2 confirmed i…
Postzygotic BRAF p.Lys601Asn Mutation in Phacomatosis Pigmentokeratotica with Woolly Hair Nevus and Focal Cortical Dysplasia
2016
International audience
Determinación de parámetros clínico-patológicos y moleculares implicados en la regresión espontánea de neoplasias melanocíticas cutáneas
2015
Antecedentes y Objetivos: existe evidencia acumulada de que tanto el melanoma como los nevus melanocíticos tienen la capacidad de estimular la respuesta inmune. Se ha demostrado que la regresión en el melanoma es 6 veces más frecuente que en otras neoplasias malignas, y aunque la regresión completa de melanomas es un evento excepcional, se ha constatado que la regresión parcial es frecuente, ya que ocurre entre un 10 y un 35% de los mismos. Desde un punto de vista exclusivamente histológico, cuando la regresión es completa, es muy difícil determinar la naturaleza biológica de la lesión previa, y en la mayoría de ocasiones, tan sólo el desarrollo de metástasis en el seguimiento posterior del…
Evaluation of DNA ploidy and degree of DNA abnormality in benign and malignant melanocytic lesions of the skin using video imaging.
2000
BACKGROUND Making a morphologic distinction between benign and malignant melanocytic tumors of the skin is frequently difficult, especially because “gray zones” between these lesions often exist. DNA image cytometry as an adjuvant method for the diagnosis and prognostic prediction of premalignant lesions and malignant tumors of many other organs is already well established. The aim of this study was to determine whether DNA image cytometry is helpful in distinguishing benign from malignant melanocytic lesions and whether cytometry would give valid information with which to predict the prognoses associated with malignant melanomas. METHODS DNA image cytometry was performed on 127 benign and …
Beta-catenin and surviving expression in keratocystic odontogenic tumor (KCOT). A comparative immunohistochemical study in primary, recurrent and nev…
2013
Aim: To determine the epithelial expression of ß-catenin and survivin in sporadic (primary, and recurrent) and nevoid basal cell carcinoma syndrome (NBCCS) keratocystic odontogenic tumour (KCOT) in order to assess activation of the ß-catenin pathway and evidence of apoptotic inhibition, processes that may contribute to the known differences in their biological behaviour. Materials and Methods: Sections from 40 cases of KCOT (19 sporadic/primary; 9 sporadic/recurrent and 12 NBCCS-associated) were immunohistochemically stained for ß-catenin and survivin. The extent and intensity of immunoreactivity within the lining epithelium was assessed, using semi-quantitative scales, independently by two…
Spontaneous regression of multiple melanocytic nevi after melanoma: report of 3 cases.
2014
Complete spontaneous regression of multiple melanocytic nevi after melanoma is an extremely rare phenomenon. We report 3 cases of patients with a history of melanoma that showed regression of almost all melanocytic nevi over time. One of the patients had 2 simultaneous primary cutaneous melanomas without metastasis. In the other 2 patients, regression of the melanocytic nevi was seen after the development of metastasis in lymph nodes. These patients had spontaneously developed an efficient immune response against melanocytes, and they would represent paradigmatic examples of the spontaneous immune responses in melanoma patients. Better understanding of the mechanisms involved in the complet…
Immunohistochemical expression of Skp2 protein in oral nevi and melanoma
2013
Objective: The aim of this study was to analyze the immunohistochemical expression of Skp2 protein in 38 oral nevi and 11 primary oral melanomas. Study Design: Expression of this ubiquitin protein was evaluated by immunohistochemistry in 49 oral melanocytic lesions, including 38 intramucosal nevi and 11 primary oral melanomas. The labeling index (LI) was assessed considering the percentage of cells expressing nuclear positivity out of the total number of cells, counting 1000 cells per slide. Results: Skp2 protein was rarely expressed in intramucosal nevi, in contrast to oral melanomas, which showed high levels of this protein. Conclusion: These results indicate that Skp2 protein may play a …
Depressed indurated plaque with elastorrhexis as a distinctive lesion in Buschke‐Ollendorff syndrome
2020
Buschke-Ollendorff syndrome (BOS) is a rare autosomal dominant genodermatosis caused by heterozygous mutations in LEMD3 and characterized by connective tissue nevi and sclerotic bone lesions known as osteopoikilosis. We report a family with three individuals affected by BOS, two of whom manifested clinical and histopathological peculiarities, presenting with a depressed indurated plaque as the main cutaneous manifestation instead of the classic connective tissue nevi. Notable elastorrhexis was present in both biopsies.