Sarcopedia

IntermediateSoft tissue

Angiomatoid fibrous Histiocytoma

Synonyms: AFH, angiomatoid malignant fibrous histiocytoma

Can mimic haematoma or cyst clinically and radiologically

Quick Facts

Behaviour

Intermediate

Category

Soft tissue

Synonyms

  • AFH
  • angiomatoid malignant fibrous histiocytoma

Category

Soft tissue

Behaviour

Intermediate

Gender

M = F

Tissue of Origin

Uncertain

Epidemiology

  • Rare intermediate-grade soft tissue tumour
  • Peak incidence in children and young adults (1st–3rd decades)
  • 0.3% of soft tissue tumours

Clinical Features

  • Slow-growing subcutaneous nodule
  • Can be associated with systemic symptoms: fever, anaemia, weight loss (paraneoplastic)
  • Occasionally pulsatile or fluctuant mass
  • Rarely causes metastasis

Location

  • Extremities (limbs) most common
  • Trunk
  • Head and neck region
  • Subcutaneous or deep dermal location

Imaging

  • Well-circumscribed heterogeneous mass on MRI
  • Haemorrhagic cystic spaces on T2-weighted imaging
  • Pseudoangiomatous spaces not truly Vascular
  • CT: well-defined soft tissue mass

Pathology

  • Multinodular fibrous pseudocapsule with peripheral lymphoid cuff
  • Pseudoangiomatous blood-filled spaces
  • Spindle cell fascicles with histiocytic appearance
  • EMA, desmin, CD99 positive; EWSR1 rearrangement

Genetics

  • FET gene rearrangement
  • Several translocations seen

Treatment

  • Wide local excision with clear margins
  • No standard systemic therapy for localised disease
  • Systemic therapy considered for metastatic disease (rare)

Prognosis

  • Excellent prognosis for localised disease
  • Local recurrence 15%
  • Metastasis rare (<5%) - to lymph node, liver and brain
  • Overall survival >95%

Key Points

  • Can mimic haematoma or cyst clinically and radiologically
  • EWSR1 rearrangement is diagnostically useful
  • Paraneoplastic symptoms resolve after excision
  • Intermediate classification

Workup - Blood Tests

  • FBC - anaemia if paraneoplastic syndrome present
  • ESR, CRP - may be elevated in paraneoplastic context
  • U&E, LFTs - preoperative baseline

Workup - Local Imaging

MRI with contrast of primary site

Workup - Biopsy

Core needle biopsy or excisional biopsy

Workup - Staging

CT chest - metastasis rare but should be excluded at staging

Workup - Other

MDT review with sarcoma specialist centre

Follow-up Summary

  1. Soft Tissue Tumours - Localised Extremity - Low Grade

    Routine MRI of primary site not indicated unless difficult to assess clinically

    Paraneoplastic symptoms (fever, anaemia, weight loss) resolve post-excision - reassure patient

Medical disclaimer

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