Cystic Hygroma



  • Benign congenital lymphatic mass (LM) that is cystic in nature
    • Most commonly found in the posterior triangle of the neck (75%)
    • Can be found in other sites of the body, including the axilla, superior mediastinum, groin, retroperitoneum, and lower limbs
  • Synonym(s): Cystic hygroma and lymphangioma are outdated terms for lymphatic malformation.


  • No gender predominance noted
  • Most series report no racial predominance.


  • Estimated at cases: 1/6,000 to 16,000 live births
  • 50–60% of cases found at birth, 90% seen by 2nd year of life

Etiology and Pathophysiology

  • Results from maldevelopment or obstruction of lymphatic system
    • Commonly associated with venous malformations, as both tend to develop concurrently
  • Decreased outflow of lymphatics to venous system and abnormal budding of lymphatic tissue create noncommunicating lymphatic tissue and resultant formation of cystic components.
  • Lesions are typically nonproliferative and rarely undergo spontaneous regression.


  • Karyotypic abnormalities are often present when a cystic hygroma is found by fetal US.
  • Commonly associated karyotypic abnormalities include Turner, Down, Klinefelter syndromes, and trisomies 13 and 18.
  • Genomic microarrays may provide genetic information in cases of abnormal US with normal karyotype (1)[A].

Risk Factors

Associated with advanced maternal age or from environmental factors like maternal virus infection or alcohol abuse during pregnancy (2)

General Prevention

  • Large lesions may be seen prenatally during 1st or 2nd trimester with fetal US or MRI.
  • Bianchi et al. (2)[B] accurately identified 107 of 113 aneuploid cases of cystic hygromas previously diagnosed with chorionic villus using massively parallel sequencing, which is a noninvasive modality.
When diagnosed prenatally, overall prognosis is poor. More specifically, the prenatal finding of septated cystic hygroma carries a worse prognosis due to a progression to nonimmune hydrops. Diagnosis following birth is more associated with a better prognosis.

Commonly Associated Conditions

  • Turner syndrome
  • Down syndrome
  • Klinefelter syndrome
  • Trisomy 13
  • Trisomy 18
  • Cardiac abnormalities
  • Noonan syndrome
  • Multiple pterygium syndrome
  • Achondroplasia
  • Fetal alcohol syndrome
  • Fetal hydrops

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