Soft tissue



Topic Completed: 10 September 2021

Minor changes: 30 September 2021

Copyright: 2002-2022,, Inc.

PubMed Search: Molecular / cytogenetics soft tissue[TI]

Borislav A. Alexiev, M.D.
Jose G. Mantilla, M.D.
Page views in 2021: 1,806
Page views in 2022 to date: 115
Cite this page: Alexiev BA, Mantilla JG. Molecular. website. Accessed January 19th, 2022.
Definition / general
  • This topic contains characteristic molecular alterations for topics in our Soft tissue and Bone & joints chapters
  • The intent is NOT to catalog every alteration identified, just those considered characteristic
  • More information is listed in the linked topic
  • Most sarcomas are cytogenetically complex neoplasms
  • Recurrent genetic alterations are seen in a subset of bone and soft tissue neoplasms
    • Point mutations: detection may aid in diagnosis or allow targeted therapy
    • Chromosomal rearrangements: recurrent gene fusions can be useful for diagnosis
    • Copy number alterations
Alveolar soft part sarcoma
Aneurysmal bone cyst, primary
Angiomatoid fibrous histiocytoma
Angiosarcoma, radiation associated
Chondroid lipoma of soft tissue
Chondrosarcoma, myxoid, extraskeletal (EMC)
Chordoma, poorly differentiated
Clear cell sarcoma
Dermatofibrosarcoma protuberans / giant cell fibroblastoma
Desmoid type fibromatosis
Desmoplastic fibroblastoma
Desmoplastic small round cell tumor
Endometrial stromal sarcoma
Epithelioid sarcoma
Ewing sarcoma / PNET, extraosseous
  • t(11;22)(q24;q12) - EWSR1-FLI1 fusion gene
  • t(2;22)(q33;q12) - EWSR1-FEV fusion gene
  • t(7,22)(p22;q12) - EWSR1-ETV1 fusion gene
  • t(17;22)(q12;q12) - EWSR1-ETV4 fusion gene
  • t(21;22)(q22;q12) - EWSR1-ERG fusion gene
  • t(16;21)(p11;q22) - FUS-ERG fusion gene
  • See Ewing sarcoma / PNET, extraosseous
  • Reference: Int J Mol Sci 2018;19:3784
Ewing sarcoma-like small blue round cell tumor
Giant cell tumor of bone
Infantile fibrosarcoma / mesoblastic nephroma
Inflammatory myofibroblastic tumor
  • t(12;14)(q13-15;q23-24) or related changes involving HMGA2 / HMGIC at 12q13-15
  • See Lipoma
Lipoma, spindle cell / pleomorphic
Liposarcoma, myxoid / round cell variants
Liposarcoma, well differentiated / dedifferentiated
Low grade fibromyxoid sarcoma / sclerosing epithelioid fibrosarcoma
Malignant peripheral nerve sheath tumor
Mesenchymal chondrosarcoma
Myoepithelioma of soft tissue
Nodular fasciitis
NTRK rearranged spindle cell neoplasm
  • NTRK rearranged mesenchymal neoplasms show variable morphologic patterns, including lipofibromatosis-like neural tumor, solitary fibrous tumor-like, inflammatory myofibroblastic tumor-like, infantile fibrosarcoma, dermatofibrosarcoma protuberans-like and malignant peripheral nerve sheath tumor-like spindle cell neoplasms and various histologic grades from low to high grade, as well as benign forms (Mod Pathol 2021;34:396)
  • Pan-TRK IHC is a reliable diagnostic marker that can be used as a surrogate marker for identification of NTRK fusion in the appropriate setting (young age, morphology) to help discover these rare tumors
  • Expensive RNA based next generation sequencing (NGS) to detect / confirm specific fusions needs to be performed if patients are candidates for targeted therapy
  • See Pan-TRK (EPR17341) [NTRK]
Ossifying fibromyxoid tumor
Rhabdomyosarcoma, alveolar
Round cell sarcoma with EWSR1-non-ETS fusions
  • Tumors with non-ETS gene partners were previously designated Ewing-like sarcoma but are now classified as round cell sarcoma with EWSR1-non-ETS fusions in the latest 2020 WHO classification
  • There may be significant correlations between fusion subtype and age at presentation, primary tumor sites and overall survival in these patients (Genes Chromosomes Cancer 2020;59:525)
Sarcoma with BCOR genetic alterations
  • BCOR-CCNB3 sarcoma (BCS) is a recently defined genetic entity among undifferentiated round cell sarcomas, initially classified as and treated similarly to the Ewing sarcoma (ES) family of tumors
  • In contrast to ES, BCS shows consistent BCOR overexpression and preliminary evidence suggests that these tumors share morphologic features with other tumors harboring BCOR genetic alterations, including BCOR internal tandem duplication (ITD) and BCOR-MAML3 (Am J Surg Pathol 2018;42:604)
  • BCOR - BCL6 transcriptional corepressor is located at Xp11.4 locus (Genes Dev 2000;14:1810, J Clin Pathol 2020;73:314)
  • See BCOR
Synovial sarcoma
Tenosynovial giant cell tumor
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