Molecular techniques for predicting behaviour in melanocytic neoplasms

Diagnostic Algorithm to Subclassify Atypical Spitzoid Tumors in Low and High Risk According to Their Methylation Status

“…Various approaches have been used over the years to correctly categorize and prognosticate ASTs, including immunohistochemical techniques ( p16 , ki67 or HMB45 ) [ 4 ]; analysis of copy number variations (CNV) by comparative genomic hybridization (CGH) [ 5 ]; fluorescence in situ hybridization (FISH) [ 6 , 7 ]; genetic point mutations [ 8 ] in genes, such as HRAS [ 9 , 10 ], NRAS [ 9 ], BRAF [ 11 ] or TERT [ 12 , 13 ]; and kinase fusions [ 14 ] in genes such as ROS1 [ 15 ], ALK [ 16 ] and NTRK1 [ 17 ]. In fact, a diagnostic algorithm for ASTs based on the combination of immunohistochemical techniques, FISH and CGH has been described [ 18 ], although the diagnostic value of FISH for AST tumors is limited due to their heterogeneity; and lower than for SN and SM [ 4 , 6 , 19 ].…”

PRAME Expression in Mucosal Melanoma of the Head and Neck Region

“…5,6 In recent years, several molecular tools, such as fluorescence in situ hybridization (FISH), comparative genomic hybridization, and next-generation sequencing have been implemented to aid in improving the diagnosis of melanocytic tumors. [7][8][9][10] Unfortunately, the rarity of MM-H&N and the limited literature data on specific genetic mutations (as TERT promoter mutations) and molecular tests (FISH) distinguishing MM-H&N from benign mucosal melanocytic lesions of the head and neck region (MBML-H&N), limits their adoption in this diagnostic field. [1][2][3][4][5][6][11][12][13][14][15] The recent introduction of PRAME (PReferentially expressed Antigen in MElanoma) has again shifted interest to using immunohistochemistry for the diagnosis of melanocytic lesions.…”

“…Besides, in this site it is difficult to benefit from clinical-dermatoscopic correlation (as in the cutaneous counterpart), the samples are often poorly cellular incisional biopsies and/or highly fragmented samples, and some atypical histologic features (epidermal effacement and pagetoid spread of melanocytes in suprabasal layers) are rarely found in the early stage of disease 5,6. In recent years, several molecular tools, such as fluorescence in situ hybridization (FISH), comparative genomic hybridization, and next-generation sequencing have been implemented to aid in improving the diagnosis of melanocytic tumors 7–10. Unfortunately, the rarity of MM-H&N and the limited literature data on specific genetic mutations (as TERT promoter mutations) and molecular tests (FISH) distinguishing MM-H&N from benign mucosal melanocytic lesions of the head and neck region (MBML-H&N), limits their adoption in this diagnostic field 1–6,11–15.…”