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Flashcards in Muscle tumours Deck (11):

What is Leiomyosarcoma?

  • an Aggressive sarcoma thought to arise from the Smooth Muscle cells lining small blood vessels
    • it may either occur in soft tissue (uterus) or in the bone
  • fewer than 100 case reports of extra-facial leiomyosarcoma of bone
  • mean age 5th/6th decade
  • location
    • Metaphysis of long bones (occasional diaphyseal)
    • femur, tibia, ilium and humerus
  • Prognosis
    • LSM of bone in adults
      • 25% recurrence rate 
      • 25% metastatis rate
      • 75% survival at 3 years w tx

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What is the presentation of a pt with leiomyosarcoma?

  • Bone pain
  • Palpable mass
  • typical duration of symptoms prior to dx is 6months


  • Pelvic masses- difficult on inspection
  • can be tender or non tender to palpation
  • masses will be firm


What is seen on xrays of leiomyosarcoma?

  • Involved extremity
  • purely osteolyic lesion will ill-distinct margins, moth-eaten , or permeative pattern of bone destruction
  • primarily intra-medullary but may extend into soft tissues
  • chest xray
    • for all staging ? mets

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What is seen on MRI of leiomyosarcoma?

  • Appears dark on T1 similar to muscle tissue
  • appearas heterogenous on T2 w areas of increased signal intensity

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What is the histology of leiomyosarcoma?

  • Spindle cell neoplasm w similar characteristics shared between osseous & soft tissue of this disease
  • Cigar shaped nuclei 
  • cells arranged into fascicles along with myofibrils running parallel
  • presence of actin and vimentin immunoreactivity

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What is the tx of leiomyosarcoma?

Non operatively

  • Chemotherapy
    • better survival when combined w surgery
    • variable response to chemo
    • large pelvic masses not amenable to surgery
    • diffuse met disease
  • Radiotherapy
    • variable response, contraverisal use


  • Early wide resection of primary lesion and 2ary reconstruciton
    • standard to local disease
    • clean margin is important goal of surgical resection
    • neoadjuvant/adjuvant chemo contraversial



What is Rhabdomyosarcoma?

  • A Malignant tumour of the primitive mesechyme
  • most common Sarcoma in children
  • 4 types
    • Embyronal ( in infants/young children)
    • Alveolar ( adolescent/young adults)
    • Botryoid ( infants/young children in vagina)
    • Pleomorphic ( older pts 40-70)
  • Genetics
    • common t(2:13) translocation= aveolar type
    • froms Pax3-FKHR fuson protein
    • assoc w high rate of metastatic disease
  • Mets
    • nodal mets- consider sentiel node biopst part of tx
    • bone marrow biopsy for staging- bone marrow mets worse prognosis

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What is the prognosis of Rhabdomyosarcoma?

  • 5 yr suvival
  • embryonal= 80%
  • Aveolar= 60%
  • Botryoid- uniformly fatal, <30% suvival 5 yr from dx
  • Pleomorphic- 25%


What are the symptoms of Rhabdomyosarcoma?

  • Rapidly growing painless mass
  • Most lesions occur in head/neck, genitourinary system or retroperitoneum


What is seen on imaging of Rhabdomyosarcoma?

  • CT
    • ct chest for staging
  • MRI
    • Non diagnostic but crucial to plan tx
    • Rhabdomyosarcoma appear like other soft tissue sarcomas=
      • Dark T1
      • Bright T2


what is the tx of Rhabdomyosarcoma

Non operative

  • Chemotherapy alone
    • only in pts with widespread mets
  • Radiation therapy alone
    • for unresectable tumours close to margins


  • Wide surgical excision with chemotherapy
    • in ​Paediatric Rhabdomyosarcoma
    • Chemo not effective in adult Rhabdomyosarcoma
    • Vincristine, dactinomycin, cyclosphosphamide


  • ​Wide surgical excision with radiotherapy
    • for adult pleomorphic Rhabdomyosarcoma