Rhabdomyoblast

A rhabdomyoblast is a cell type which is found in some rhabdomyosarcomas.[1] When found histologically, a rhabdomyoblast aids the diagnosis of embryonal, alveolar, spindle cell/sclerosing, and pleomorphic rhabdomyosarcomas; however, in a tumor, expression of the rhabdomyoblast phenotype is not the only factor in diagnosing a rhabdomyosarcoma.[2][3] Mesenchymal malignancies can exhibit this phenotype as well.[3] Immunohistochemistry techniques allow for the sensitive detection of desmin, vimentin, muscle specific actin, and MyoD1.[4] Similarly the rhabdomyoblast phenotype can be detected morphologically.[3]

Rhabdomyoblasts are early stage mesenchymal cells, having the potential to differentiate into a wide range of skeletal cells.[5] Each stage of differentiation exhibits unique and distinguishable histological characteristics. In its initial form, stellate cells with amphiphilic cytoplasm and ovular central nuclei are observed. Commonly referred to as rhabdoid features, the maturing rhabdomyoblast will likely exhibit low levels of eosinophilic cytoplasm in proximal distances to the nucleus.[6] As maturation and differentiation progress, the cell's cytoplasmic levels of white blood cells increase; additionally, elongated shapes, commonly depicted as “tadpole”, “strap” and "spider cells", are observed. In the concluding phase of differentiation, the white blood cell rich cytoplasm appears bright and exhibits cross-striation.[5] The highly regulated organization of actin and myosin microfilaments in contractile proteins results in this appearance.[7]

With advancements in the medical field, the number of tumors connected to the rhabdomyoblastic phenotype has increased.[3] Recently, the lesion cells of 10 inflammatory tumors were found to possess the rhabdomyoblastic phenotype.[3] Continued research is necessary for precise molecular characterization of the rhabdomyoblastic phenotype and its use in patient case management.[3]

  1. ^ Holland-Frei Cancer Medicine (6th ed.). BC Decker. 2003. ISBN 978-1-55009-213-4.
  2. ^ Rosenberg AE (2010). "Bones, Joints, and Soft Tissue Tumors". In Robbins SL, Kumar V, Cotran RS (eds.). Robbins and Cotran pathologic basis of disease (8th ed.). Philadelphia, PA: Saunders/Elsevier. p. 1253. ISBN 978-1-4160-3121-5. OCLC 212375916.
  3. ^ a b c d e f Leiner J, Le Loarer F (January 2020). "The current landscape of rhabdomyosarcomas: an update". Virchows Archiv. 476 (1): 97–108. doi:10.1007/s00428-019-02676-9. PMID 31696361. S2CID 207911529.
  4. ^ Merrow Jr AC (2017). Diagnostic imaging. Pediatrics (3rd ed.). Philadelphia, PA. ISBN 978-0-323-44321-0. OCLC 964919393.{{cite book}}: CS1 maint: location missing publisher (link)
  5. ^ a b Angelico G, Piombino E, Broggi G, Motta F, Spadola S (2017). "Rhabdomyoblasts in Pediatric Tumors: A Review with Emphasis on their Diagnostic Utility". Journal of Stem Cell Therapy and Transplantation. 1 (1): 008–016. doi:10.29328/journal.jsctt.1001002.
  6. ^ Robertus JL, Harms G, Blokzijl T, Booman M, de Jong D, van Imhoff G, et al. (April 2009). "Specific expression of miR-17-5p and miR-127 in testicular and central nervous system diffuse large B-cell lymphoma". Modern Pathology. 22 (4): 547–555. doi:10.1038/modpathol.2009.10. PMID 19287466. S2CID 12768829.
  7. ^ Sweeney HL, Hammers DW (February 2018). "Muscle Contraction". Cold Spring Harbor Perspectives in Biology. 10 (2): a023200. doi:10.1101/cshperspect.a023200. PMC 5793755. PMID 29419405.