Both Spitz naevi and spitzoid melanoma had a lower combined BRAF and NRAS mutation frequency compared with common acquired naevi (P = 0.0001) and common forms of melanoma (P = 0.0072), respectively.
In contrast to the majority of cutaneous melanomas, activating hot-spot mutations in B-RAF or N-RAS were not involved in the pathogenesis of Spitzoid melanoma.
We evaluated the immunohistochemical expression of p16, and the presence of CDKN2A genetic alterations detected through fluorescence in situ hybridization (FISH) and multiplex ligation-dependent probe amplification (MLPA), in a series of 130 Spitz nevi, 20 atypical spitzoid tumors, and 11 spitzoid melanoma.
This case demonstrates the presence of clonal heterogeneity of losses of chromosome 9 and p16 protein expression within a single spitzoid melanoma, challenging a robust application of p16 expression detected only by immunohistochemical staining in determining the diagnosis of spitzoid melanoma.
We therefore conclude that HRAS mutation analysis may be a useful diagnostic tool to help differentiate between Spitz nevus and Spitzoid melanoma, thereby reducing the frequency of overdiagnosis of melanoma, and to help predict the biological behavior of a STUMP.
Both Spitz naevi and spitzoid melanoma had a lower combined BRAF and NRAS mutation frequency compared with common acquired naevi (P = 0.0001) and common forms of melanoma (P = 0.0072), respectively.
In contrast to the majority of cutaneous melanomas, activating hot-spot mutations in B-RAF or N-RAS were not involved in the pathogenesis of Spitzoid melanoma.
Thus, MAP3K8 rearrangements-uncovered by comprehensive clinical sequencing of a single case-are the most common genetic event in spitzoid melanoma, are present in adult melanomas and could be amenable to MEK inhibition.
Thus, MAP3K8 rearrangements-uncovered by comprehensive clinical sequencing of a single case-are the most common genetic event in spitzoid melanoma, are present in adult melanomas and could be amenable to MEK inhibition.
Our results indicate that Nestin could allow to discriminate between AST and malignant spiztoid melanoma; the typical dermoscopic pattern is also associated with benign nevi in contrast to the atypical pattern that accumunates AST and malignant spitzoid melanoma.
We evaluated the ability of the fluorescence in situ hybridization (FISH) assay-designed to detect the copy number of the RREB1 (6p25), MYB (6q23) and CCND1 (11q13) genes and of centromere 6 (Cep 6)-in order to distinguish between Spitz naevus and spitzoid melanoma.
We evaluated the ability of the fluorescence in situ hybridization (FISH) assay-designed to detect the copy number of the RREB1 (6p25), MYB (6q23) and CCND1 (11q13) genes and of centromere 6 (Cep 6)-in order to distinguish between Spitz naevus and spitzoid melanoma.
We evaluated the ability of the fluorescence in situ hybridization (FISH) assay-designed to detect the copy number of the RREB1 (6p25), MYB (6q23) and CCND1 (11q13) genes and of centromere 6 (Cep 6)-in order to distinguish between Spitz naevus and spitzoid melanoma.