Muscle tumours

Question 1

What is Leiomyosarcoma?

Answer 1

• 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

Question 2

What is the presentation of a pt with leiomyosarcoma?

Answer 2

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

O.E

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

Question 3

What is seen on xrays of leiomyosarcoma?

Answer 3

• 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

Question 4

What is seen on MRI of leiomyosarcoma?

Answer 4

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

Question 5

What is the histology of leiomyosarcoma?

Answer 5

• 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

Question 6

What is the tx of leiomyosarcoma?

Answer 6

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

Operative

• 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

Question 7

What is Rhabdomyosarcoma?

Answer 7

• 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

Question 8

What is the prognosis of Rhabdomyosarcoma?

Answer 8

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

Question 9

What are the symptoms of Rhabdomyosarcoma?

Answer 9

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

Question 10

What is seen on imaging of Rhabdomyosarcoma?

Answer 10

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

Question 11

what is the tx of Rhabdomyosarcoma

Answer 11

Non operative

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

Operative

• 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