Absence of mutations of the BRAF gene in malignant melanoma of soft parts (clear cell sarcoma of tendons and aponeuroses)

Malignant melanoma of soft parts (MMSP), also called clear cell sarcoma of tendons and aponeuroses, is cytogenetically characterized by the t(12;22)(q13;q12) resulting in the chimeric EWSR1/ATF1 gene. MMSP shares a number of morphologic, histologic, and immunohistochemical features with malignant melanoma of the skin, causing diagnostic difficulties in the distinction between MMSP and metastatic malignant melanoma with an unknown primary site. Recently, a high incidence of activating mutations in the kinase domain of the BRAF gene has been reported in malignant melanoma of the skin. The most common mutation (V599E) is the T1796A substitution in exon 15, leading to an exchange of valine for glutamic acid at position 599. Because of the extensive clinical, histologic, and immunohistochemic similarities with melanoma, we decided to analyze whether MMSP also has mutations in the BRAF gene. Eight MMSP with an EWSR1/ATF1 chimeric transcript, one soft tissue metastasis of a malignant melanoma of the skin, and one malignant melanoma cell line were examined. Both conventional melanomas had the exon 15 T1796A (V599E) mutation, but none of the MMSP was found to harbor any mutation in exon 11 or 15 of the BRAF gene. Our data further emphasize that MMSP and conventional malignant melanoma develop through different genetic pathways

Pseudomyogenic hemangioendothelioma: t(7;19)(q22;q13) SERPINE1/FOSB

Pseudomyogenic hemangioendothelioma (PHE) is an intermediate malignant vascular tumor primarily affecting soft tissues in children and young adults. The molecular basis of this neoplasm is unknown. Chromosome banding analysis, fluorescence in situ hybridization (FISH), mRNA sequencing, RT-PCR, and quantitative real-time PCR have shown that PHEs are characterized by a balanced translocation t(7;19)(q22;q13), resulting in the fusion of the SERPINE1 and FOSB genes. The role of SERPINE1, which is highly expressed in vascular cells, in this gene fusion is probably to provide a strong promoter for FOSB. FOSB encodes a transcription factor belonging to the FOS family of proteins, which together with members of the JUN family of transcription factors are major components of the Activating Protein 1 (AP-1) complex

Soft Tissue Tumors: t(X;20)(p11.23;q13.33) in Biphasic Synovial Sarcoma

Review on Soft Tissue Tumors: t(X;20)(p11.23;q13.33) in Biphasic Synovial Sarcoma, with data on clinics, and the genes involved

Inflammatory Leiomyosarcoma and Histiocyte-rich Rhabdomyoblastic Tumor : a clinicopathological, immunohistochemical and genetic study of 13 cases, with a proposal for reclassification as Inflammatory Rhabdomyoblastic Tumor

Inflammatory leiomyosarcoma (ILMS), defined as a malignant neoplasm showing smooth muscle differentiation, a prominent inflammatory infiltrate, and near-haploidization , is a very rare soft tissue tumor with a generally favorable prognosis. The morphologic features of histiocyte-rich rhabdomyoblastic tumor (HRRMT) are similar to those of ILMS, although this lesion shows by definition a skeletal muscle phenotype. Recent gene expression profiling and immunohistochemical studies have also suggested that ILMS and HRRMT may be related. We studied the clinicopathologic, immunohistochemical and genetic features of four cases previously classified as ILMS and nine classified as HRRMT. Tumors from both groups tended to occur in the deep soft tissues of the extremities of young to middle-aged males and exhibited indolent behavior. Morphologically, all were well-circumscribed, often encapsulated, and showed a striking histiocyte-rich inflammatory infiltrate admixed with variably pleomorphic tumor cells showing spindled and epithelioid to rhabdoid morphology, eosinophilic cytoplasm, and prominent nucleoli, but few, if any, mitotic figures. Immunohistochemically, the tumor cells expressed desmin, alpha-smooth muscle actin, and the rhabdomyoblastic markers PAX7, MyoD1, and myogenin. H-caldesmon expression was absent in all cases, using the specific h-CD antibody. Karyotypic study (1 HRRMT) and genome-wide copy number analysis (7 HRRMT, OncoScan SNP assay), revealed near-haploidization in four cases, with subsequent genome doubling in one, an identical phenotype to that seen in ILMS. We propose reclassification of ILMS and HRRMT as inflammatory rhabdomyoblastic tumor , a name which accurately describes the salient morphologic and immunohistochemical features of this distinctive tumor, as well as its intermediate (rarely metastasizing) clinical behavior

Reclassification and subtyping of so-called malignant fibrous histiocytoma of bone: comparison with cytogenetic features

<p>Abstract</p> <p>Background</p> <p>The diagnostic entity malignant fibrous histiocytoma (MFH) of bone is, like its soft tissue counterpart, likely to be a misnomer, encompassing a variety of poorly differentiated sarcomas. When reviewing a series of 57 so-called MFH of bone within the framework of the EuroBoNeT consortium according to up-to-date criteria and ancillary immunohistochemistry, a fourth of all tumors were reclassified and subtyped.</p> <p>Methods</p> <p>In the present study, the cytogenetic data on 11 of these tumors (three myoepithelioma-like sarcomas, two leiomyosarcomas, one undifferentiated pleomorphic sarcoma with incomplete myogenic differentiation, two undifferentiated pleomorphic sarcomas, one osteosarcoma, one spindle cell sarcoma, and one unclassifiable biphasic sarcoma) are presented.</p> <p>Results</p> <p>All tumors were high-grade lesions and showed very complex karyotypes. Neither the overall pattern (ploidy level, degree of complexity) nor specific cytogenetic features distinguished any of the subtypes. The subgroup of myoepithelioma-like sarcomas was further investigated with regard to the status of the <it>EWSR1 </it>and <it>FUS </it>loci; however, no rearrangement was found. Nor was any particular aberration that could differentiate any of the subtypes from osteosarcomas detected.</p> <p>Conclusions</p> <p>chromosome banding analysis is unlikely to reveal potential genotype-phenotype correlations between morphologic subtypes among so-called MFH of bone.</p

Kızıl serap

Burhan Cahit'in Milliyet'te tefrika edilen Kızıl Serap adlı romanıTelif hakları nedeniyle romanın tam metni verilememiştir

Transcriptomic subtyping of malignant peripheral nerve sheath tumours highlights immune signatures, genomic profiles, patient survival and therapeutic targets

Background: Malignant peripheral nerve sheath tumour (MPNST) is an aggressive orphan disease commonly affecting adolescents or young adults. Current knowledge of molecular tumour biology has been insufficient for development of rational treatment strategies. We aimed to discover molecular subtypes of potential clinical relevance. Methods: Fresh frozen samples of MPNSTs (n = 94) and benign neurofibromas (n = 28) from 115 patients in a European multicentre study were analysed by DNA copy number and/or transcriptomic profiling. Unsupervised transcriptomic subtyping was performed and the subtypes characterized for genomic aberrations, clinicopathological associations and patient survival. Findings: MPNSTs were classified into two transcriptomic subtypes defined primarily by immune signatures and proliferative processes. “Immune active” MPNSTs (44%) had sustained immune signals relative to neurofibromas, were more frequently low-grade (P = 0.01) and had favourable prognostic associations in a multivariable model of disease-specific survival with clinicopathological factors (hazard ratio 0.25, P = 0.003). “Immune deficient” MPNSTs were more aggressive and characterized by proliferative signatures, high genomic complexity, aberrant TP53 and PRC2 loss, as well as high relative expression of several potential actionable targets (EGFR, ERBB2, EZH2, KIF11, PLK1, RRM2). Integrated gene-wise analyses suggested a DNA copy number-basis for proliferative transcriptomic signatures in particular, and the tumour copy number burden further stratified the transcriptomic subtypes according to patient prognosis (P &lt; 0.01). Interpretation: Approximately half of MPNSTs belong to an “immune deficient” transcriptomic subtype associated with an aggressive disease course, PRC2 loss and expression of several potential therapeutic targets, providing a rationale for molecularly-guided intervention trials. Funding: Research grants from non-profit organizations, as stated in the Acknowledgements.</p

Transcriptomic subtyping of malignant peripheral nerve sheath tumours highlights immune signatures, genomic profiles, patient survival and therapeutic targets

Background: Malignant peripheral nerve sheath tumour (MPNST) is an aggressive orphan disease commonly affecting adolescents or young adults. Current knowledge of molecular tumour biology has been insufficient for development of rational treatment strategies. We aimed to discover molecular subtypes of potential clinical relevance. Methods: Fresh frozen samples of MPNSTs (n = 94) and benign neurofibromas (n = 28) from 115 patients in a European multicentre study were analysed by DNA copy number and/or transcriptomic profiling. Unsupervised transcriptomic subtyping was performed and the subtypes characterized for genomic aberrations, clinicopathological associations and patient survival. Findings: MPNSTs were classified into two transcriptomic subtypes defined primarily by immune signatures and proliferative processes. “Immune active” MPNSTs (44%) had sustained immune signals relative to neurofibromas, were more frequently low-grade (P = 0.01) and had favourable prognostic associations in a multivariable model of disease-specific survival with clinicopathological factors (hazard ratio 0.25, P = 0.003). “Immune deficient” MPNSTs were more aggressive and characterized by proliferative signatures, high genomic complexity, aberrant TP53 and PRC2 loss, as well as high relative expression of several potential actionable targets (EGFR, ERBB2, EZH2, KIF11, PLK1, RRM2). Integrated gene-wise analyses suggested a DNA copy number-basis for proliferative transcriptomic signatures in particular, and the tumour copy number burden further stratified the transcriptomic subtypes according to patient prognosis (P &lt; 0.01). Interpretation: Approximately half of MPNSTs belong to an “immune deficient” transcriptomic subtype associated with an aggressive disease course, PRC2 loss and expression of several potential therapeutic targets, providing a rationale for molecularly-guided intervention trials. Funding: Research grants from non-profit organizations, as stated in the Acknowledgements.</p