Soft tissue
Skeletal muscle
Sclerosing rhabdomyosarcoma

Author: Vijay Shankar, M.D. (see Authors page)

Revised: 26 September 2016, last major update November 2012

Copyright: (c) 2002-2016, PathologyOutlines.com, Inc.

PubMed Search: Sclerosing rhabdomyosarcoma

Cite this page: Sclerosing rhabdomyosarcoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/softtissuesclerosingrhabdo.html. Accessed October 17th, 2017.
Definition / general
Clinical features
Case reports
Gross description
  • 4 to 8 cm
Microscopic (histologic) description
  • Lobules and infiltrating cords of small round malignant cells embedded in densely hyalinized matrix with chondroid and osteoid-like appearance
  • May have pseudovascular growth pattern, rhabdomyoblastic differentiation with strap cells, areas suggestive of spindle cell rhabdomyosarcoma, extensive mitotic activity (> 20 mitotic figures / 20 high power fields)
  • No / focal embryonal or alveolar patterns
  • No tumor giant cells
  • No definite lacunae or matrix calcification present
Positive stains
Negative stains
Molecular / cytogenetics description
  • No t(2;13) of alveolar rhabdomyosarcoma
  • Specific MDM2/HMGA2 amplification at 12q13-15 in 1 case (Hum Pathol 2009;40:1347)
  • Loss of 10q22, loss of chromosome Y and gain of #18 in one case (Virchows Arch 2006;449:572)
  • Pattern of numerical changes similar to embryonal rhabdomyosarcoma in one case (Virchows Arch 2005;446:64)
  • Hyperdiploidy, tetraploidy, del 1, Trisomy 11, 16, monosomy 22
Electron microscopy description
  • Irregularly distributed disorganized filament in richly collagenized matrix
  • No Z-bands
Differential diagnosis