Melanoma types by in vivo reflectance confocal microscopy correlated with protein and molecular genetic alterations: A pilot study.

Cutaneous melanoma (CM) is one of the most prevalent skin cancers, which lacks both a prognostic marker and a specific and lasting treatment, due to the complexity of the disease and heterogeneity of patients. Reflectance confocal microscopy (RCM) in vivo analysis is a versatile approach offering immediate morphological information, enabling the identification of four primary cutaneous RCM CM types. Whether RCM CM types are associated with a specific protein and molecular genetic profiles at the tissue level remains unclear. The current pilot study was designed to identify potential correlations between RCM CM types and specific biological characteristics, combining immunohistochemistry (IHC) and molecular analyses. Eighty primary CMs evaluated at patient bedside with RCM (type 1 [19, 24%], type 2 [12, 15%], type 3 [7, 9%] and type 4 [42, 52%]) were retrospectively evaluated by IHC stains (CD271, CD20, CD31, cyclin D1), fluorescence in situ hybridization FISH for MYC gain and CDKN2A loss and molecular analysis for somatic mutations (BRAF, NRAS and KIT). RCM CM types correlated with markers of stemness property, density of intra-tumoral lymphocytic B infiltrate and cyclin D1 expression, while no significant association was found with blood vessel density nor molecular findings. RCM CM types show a different marker profile expression, suggestive of a progression and an increase in aggressiveness, according to RCM morphologies.

Primary Orbital Synovial Sarcoma Mimicking a Periocular Cyst.

Synovial sarcoma (SS) is a high-grade soft-tissue sarcoma occurring predominantly in older children and young adults. Only approximately 7% occur in the head and neck region, with SS representing less than 0.1% of all head and neck cancers. Orbital location is exceedingly rare with only 8 cases reported so far in the literature. It is noted for its propensity for late local recurrences and metastases. Histologically, SS is monophasic, biphasic, or poorly differentiated and harbors a specific chromosomal translocation t(X;18)(p11.2;q11.2) in >95% of cases. In this article, we describe a case of monophasic SS primarily arising in the left supero-nasal orbital region in a 24-year-old woman, clinically mistaken for a periocular cyst. The case is peculiar for its highly unusual location and for its clinical deceptively benign appearance.

Assessment of the InSiGHT Interpretation Criteria for the Clinical Classification of 24 MLH1 and MSH2 Gene Variants.

Pathogenicity assessment of DNA variants in disease genes to explain their clinical consequences is an integral component of diagnostic molecular testing. The International Society for Gastrointestinal Hereditary Tumors (InSiGHT) has developed specific criteria for the interpretation of mismatch repair (MMR) gene variants. Here, we performed a systematic investigation of 24 MLH1 and MSH2 variants. The assessments were done by analyzing population frequency, segregation, tumor molecular characteristics, RNA effects, protein expression levels, and in vitro MMR activity. Classifications were confirmed for 15 variants and changed for three, and for the first time determined for six novel variants. Overall, based on our results, we propose the introduction of some refinements to the InSiGHT classification rules. The proposed changes have the advantage of homogenizing the InSIGHT interpretation criteria with those set out by the Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA) consortium for the BRCA1/BRCA2 genes. We also observed that the addition of only few clinical data was sufficient to obtain a more stable classification for variants considered as "likely pathogenic" or "likely nonpathogenic." This shows the importance of obtaining as many as possible points of evidence for variant interpretation, especially from the clinical setting.

A Founder Effect for the HGD G360R Mutation in Italy: Implications for a Regional Screening of Alkaptonuria.

We sought to establish rapid and specific genotyping methods for G360R mutation and for seven tightly linked markers in the homogentisate dioxygenase gene to address the question of whether G360R is a mutational hot spot or the result of a founder effect, as it has been repeatedly found in alkaptonuric patients from a geographic isolate in Italy.For G360R and single nucleotide polymorphism genotyping, high-resolution melting analysis was performed. Microsatellites were analysed by multiplex PCR and capillary electrophoresis. To investigate the natural history of the G360R mutation, we genotyped markers in 52 controls and in 8 unrelated patients from the UK and USA, who also segregated the G360R mutation, and calculated its age using DMLE+2.3 software.A distinct G360R-bearing haplotype was identified in all patients of Caucasian descent. Estimated mutation age was 545 generations (95% credible set, 402-854), suggesting that G360R arose in an ancestor who lived 8,000-10,000 years BC. Archaeological, historical and demographic data support that a G360R carrier has settled the remote valley where present-day population might have a heterozygote frequency of at least 6%.Given the late health-threatening complications of alkaptonuria and a cure within reach, inhabitants of this isolate would benefit from screening and genetic counselling.

MLH1 constitutional and somatic methylation in patients with MLH1 negative tumors fulfilling the revised Bethesda criteria.

Lynch syndrome (LS) is a tumor predisposing condition caused by constitutional defects in genes coding for components of the mismatch repair (MMR) apparatus. While hypermethylation of the promoter of the MMR gene MLH1 occurs in about 15% of colorectal cancer samples, it has also been observed as a constitutional alteration, in the absence of DNA sequence mutations, in a small number of LS patients. In order to obtain further insights on the phenotypic characteristics of MLH1 epimutation carriers, we investigated the somatic and constitutional MLH1 methylation status of 14 unrelated subjects with a suspicion of LS who were negative for MMR gene constitutional mutations and whose tumors did not express the MLH1 protein. A novel case of constitutional MLH1 epimutation was identified. This patient was affected with multiple primary tumors, including breast cancer, diagnosed starting from the age of 55 y. Investigation of her offspring by allele specific expression revealed that the epimutation was not stable across generations. We also found MLH1 hypermethylation in cancer samples from 4 additional patients who did not have evidence of constitutional defects. These patients had some characteristics of LS, namely early age at onset and/or positive family history, raising the possibility of genetic influences in the establishment of somatic MLH1 methylation.