Snowstorm sign (complete hydatiform mole)

Last revised by Wedyan Yousef Alrasheed on 4 Feb 2023

Snowstorm sign in obstetric imaging is classically seen in complete hydatiform mole. It is characterized by the presence of many hydropic villi which gives the ultrasonographic appearance of a central heterogeneous mass having a solid, hyperechoic area and interspersed with a multitude of cystic areas and filling the entire uterine cavity. 

A similar sign has also been described in extracapsular breast implant ruptures.

Cases and figures

  • Case 1: snowstorm sign in hydatidiform mole
  • Case 2: complete hydatidiform mole

Imaging differential diagnosis

  • Snowstorm sign in Silicone axillary lymphadenopathy
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