Bernadette L. Koch, MD

Figure 1 (Left) Coronal CECT in a 5 year old shows a well-defined, mildly enhancing left orbital rhabdomyosarcoma image, inseparable from the left inferior rectus muscle. Notice contralateral normal inferior rectus muscle image. (Right) Coronal T1WI C+ FS MR in an 11-year-old boy with recurrent parameningeal rhabdomyosarcoma image shows intracranial extension involving the cavernous sinuses bilaterally and the right middle cranial fossa image.

Figure 2 (Left) Axial CECT in a 2-year-old girl with nasal ala RMSa image shows a well-defined mass narrowing the right anterior nasal cavity, without significant bone destruction. Lack of bone destruction in a young child with a soft tissue mass should not be interpreted as diagnostic of a benign lesion. (Right) Axial CECT in an 11 year old with left facial mass and prior history of RMSa demonstrates a large, necrotic, left masticator space recurrence image and destruction of the mandible image.



  • Rhabdomyosarcoma (RMSa)


  • Malignant neoplasm of striated muscle; most common childhood soft tissue sarcoma


General Features

  • Best diagnostic clue

    • Soft tissue mass with variable contrast enhancement

    • Bone destruction or remodeling possible

  • Location

    • Up to 40% occur in head & neck (H&N)

      • Orbit

      • Parameningeal sites: Middle ear, paranasal sinus, nasopharynx (NP), masticator space, pterygopalatine fossa, parapharyngeal space

        • Intracranial extension in up to 55%

      • All other head & neck sites including cervical neck, nasal cavity

  • Size

    • Variable, may present earlier in orbit secondary to small space and early proptosis

CT Findings

  • Invasive soft tissue mass with variable contrast enhancement

  • Osseous erosion common but not seen in all cases

MR Findings

  • Isointense T1, hyperintense T2 relative to muscle

  • Variable contrast enhancement

  • Intracranial extension in parameningeal RMSa

    • Meningeal thickening and enhancement

Imaging Recommendations

  • Best imaging tool

    • CT best to evaluate osseous erosion

    • MR best to evaluate intracranial & perineural spread

  • Protocol advice

    • Coronal post-contrast fat-saturation T1 imaging for assessment of intracranial disease

    • Axial and coronal thin section bone CT for osseous erosion

    • Include neck to rule out cervical metastatic adenopathy


Juvenile Angiofibroma

Sep 20, 2016 | Posted by in HEAD & NECK IMAGING | Comments Off on Rhabdomyosarcoma
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