Fibroid, leiomyoma

Definition: Benign smooth muscle tumor of uterus

Typically well-defined round or oval hypoechoic mass ± calcification

Myomas can grow during first 1/2 of pregnancy

Myomas can degenerate during pregnancy

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  Most common: Asymptomatic hyaline degeneration

  
  
  
  
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    Typically heterogeneous, septated, cystic myoma

  
  
  
  
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  Less common: Symptomatic hemorrhagic degeneration

  
  
  
  
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    Hyperechoic, heterogeneous, solid-appearing myoma

    
    
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    Can lead to preterm labor and pregnancy loss

  
  

Placenta can implant upon myoma

Color Doppler findings

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  Uterine vessels supply myoma

  
  
  
  
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    May see vascular pedicle to pedunculated myoma

  
  
  
  
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  Peripheral swirled pattern of flow is typical

Complications related to size, number, and location

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  Lower uterine myoma with ↑ rates of malpresentation, cesarean delivery, and postpartum hemorrhage

  
  
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  Retroplacental myoma with ↑ rates of placental insufficiency, abruption, and preterm labor

  
  
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  Multiple myomas associated with fetal growth restriction and postpartum hemorrhage

Acute pain, low-grade fever associated with hemorrhagic degeneration: MR best to show hemorrhage

Note location, type, and size of myoma in every case

Note relationship with placenta and cervix

Adnexal and pedunculated myoma can mimic ovarian mass

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  Look for blood supply from uterus

  
  
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  Look for separate ovary

If myoma is painful, consider hemorrhagic degeneration and alert provider