Sarcopedia

MalignantSoft tissue

Pleomorphic Rhabdomyosarcoma

Synonyms: Adult-type rhabdomyosarcoma, pleomorphic type

Adult variant - generally poor prognosis

Quick Facts

Behaviour

Malignant

Category

Soft tissue

Grade

High

Synonyms

  • Adult-type rhabdomyosarcoma
  • pleomorphic type

Category

Soft tissue

Behaviour

Malignant

Grade

High

Gender

M = F

Tissue of Origin

Skeletal muscle

Epidemiology

  • Rare adult variant of rhabdomyosarcoma
  • Peak incidence in older adults
  • Lower extremity predominance

Clinical Features

  • Large, rapidly growing mass
  • Often presents with advanced disease

Location

  • Lower extremity most common
  • Trunk
  • Soft tissues

Imaging

  • MRI: large heterogeneous mass
  • CT chest - metastatic staging

Pathology

  • Pleomorphic myogenic cells
  • High mitotic rate, extensive necrosis
  • Markedly atypical

Genetics

  • Variable molecular features
  • No specific fusion requirement

Treatment

  • Wide surgical excision
  • Chemotherapy and/or radiotherapy

Prognosis

  • Poor - High-grade malignancy
  • Often metastatic at presentation

Key Points

  • Adult variant - generally poor prognosis
  • Aggressive behaviour requiring multimodal therapy

Workup - Blood Tests

FBC, U&E, LFTs, LDH - baseline

Workup - Local Imaging

  • MRI primary site - local staging
  • CT chest/abdomen/pelvis - metastatic staging

Workup - Biopsy

Core needle biopsy - confirm diagnosis

Workup - Staging

CT chest/abdomen/pelvis - metastases

Follow-up Summary

  1. 1

    Year 1

    2-monthly clinical examination, CXR, plain films of primary bony site; soft tissue tumours - baseline end-of-treatment MRI/CT primary site, thereafter at clinician's discretion; radiotherapy as definitive local treatment - baseline end-of-treatment MRI/CT, then at 6 and 12 months; end of Year 1 - gonadal function and renal function

  2. 2

    Years 2–3

    3-monthly clinical examination, CXR, plain films of bony primary site; MRI of soft tissue primary site at clinician's discretion; radiotherapy patients - MRI/CT at 18 and 24 months; MUGA/ECHO 2 years post-diagnosis; annual renal function

  3. 3

    Year 4

    6-monthly clinical examination, CXR, plain films of primary site; MRI of soft tissue primary at clinician's discretion; MUGA/ECHO 4 years post-diagnosis; annual renal function

  4. 4

    Year 5

    6-monthly clinical examination, CXR, plain films of primary site; annual renal function

  5. 5

    Years 6–10

    Annual clinical examination, CXR, plain films of primary site; MUGA/ECHO 6 years post-diagnosis; annual renal function

  6. 6

    Discharge at 10 years after surgery

Medical disclaimer

The content on Sarcopedia is for educational and informational purposes only and does not constitute medical advice. It is not intended to be a substitute for professional medical diagnosis or treatment. Always consult with a qualified physician regarding any health concerns or before starting any new treatment. Reliance on any information provided on this site is solely at your own risk.