Middle ear, inner ear and temporal bone tumors - malignant

Author: Nat Pernick, M.D. (see Authors page)

Revised: 21 February 2018, last major update November 2015

Copyright: (c) 2002-2018, PathologyOutlines.com, Inc.

PubMed Search: Rhabdomyosarcoma [title] ear

Cite this page: Pernick, N. Rhabdomyosarcoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/earrms.html. Accessed November 20th, 2018.
Definition / general
  • Usually a disease of children; no gender preference
  • Painless, unilateral otitis media unresponsive to antibiotics
  • Often has invaded external canal, mastoid and meninges at presentation
  • International classification: I - superior prognosis (botryoid and spindle cell types); II - intermediate prognosis (embryonal type); III - poor prognosis (alveolar and undifferentiated types); IV - unknown prognosis (rhabdoid features)
  • Poor prognostic features: meningeal involvement; subtypes above
  • May metastasize to local lymph nodes, lung or bones
  • 5 year survival: 74% for pediatric patients
Case reports
  • Surgery, radiation therapy, chemotherapy
Gross description
  • Polypoid lesion of external or middle ear
Microscopic (histologic) description
  • Usually embryonal or botryoid types (neoplastic tumor cells growing beneath a flattened epithelium; usually small cells but occasional large cells with eosinophilic, fibrillary cytoplasm)
  • Alveolar is less common
  • Other types are rare
Microscopic (histologic) images

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Striated tumor cells

Electron microscopy description
  • Actomyosin filaments, ribonucleoprotein particles, no virus like particles
Electron microscopy images

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Thick and thin filaments with interconnecting cross-bridging

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Numerous actomyosin filaments, ribonucleoprotein and glycogen particles

Differential diagnosis
  • Inflammatory polyp / granulation tissue