Introduction
Background
Cystic hygroma was first described in 1828 by Radenbacher. Cystic hygroma (meaning "moist tumor") belongs to a group of diseases now recognized as lymphatic malformations. The discovery of a cystic hygroma has a variable effect and prognosis, depending on whether it is found in the prenatal or postnatal period. This article focuses on fetal cystic hygromas, that is, cystic hygromas that are discovered prenatally.
Related eMedicine topics:
Cystic Hygroma [Pediatrics: Surgery]
Vascular, Lymphatic Malformations
Related Medscape topics:
Specialty Site Radiology
Radiology News
CME Noonan Syndrome: What Physicians Need to Know
Lymphatic malformation.
Pathophysiology
Cystic hygromas can range from increased nuchal translucency to thin-walled cystic masses that may become larger than the fetal head.1,2 The cysts may result from a lymphatic abnormality, possibly one caused by absent or inefficient connections between the lymphatic and venous systems. The concept that correct communications between these 2 systems may develop later in the gestation of some fetuses may account for cystic areas that resolve with merely a residual amount of redundant skin (pterygium colli).
Other theories for the development of cystic hygromas include the possible abnormal sequestration of embryonic lymphatic tissue that does not communicate with normal lymph-flow channels and the budding of lymphatics that canalize to form lymph-filled cysts.
Fetal cystic hygromas vary with gestational age. First-trimester findings include nuchal translucency.3 Second-trimester findings include large, thin-walled cysts with linear internal septa, especially in the setting of Turner syndrome.4,5
Frequency
United States
Cystic hygromas occur in 1 of 200 aborted fetuses with a crown-rump length of greater than 30 mm. In pregnancies carried to term, the frequency is 1 case per 6000 births.
Mortality/Morbidity
Morbidity and mortality appear to be more common among fetuses with multilocularity or septa in their cystic hygromas than they are among fetuses that do not.6 This observation may be more indicative of true cystic hygromas than it is of simulators. Bronshtein and colleagues indicated that nonseptate cystic hygromas were transient in 98% of cases and that septate cystic hygromas were transient in only 44% of cases.7 In this same series, 72% of fetuses with septate cystic hygromas had aneuploidy. Other characteristics of cystic hygromas are as follows:
- When associated with fetal hydrops, patients with cystic hygromas have a mortality rate of almost 100%. These patients typically have karyotype abnormalities.
- Hygromas with a volume of more than 75 mm3 tend to persist. These are associated with more abnormal outcomes and chromosomal abnormalities than are smaller hygromas and hygromas discovered later in pregnancy.
- Cystic hygromas that are found in a purely anterior location on the neck are usually not related to cystic hygromas that are associated with aneuploidy and death. They have a better prognosis, and many resolve spontaneously.
Related eMedicine topics:
Hydrops Fetalis [Pediatrics: Cardiac Disease and Critical Care Medicine]
Hydrops Fetalis [Radiology]
Sex
Cystic hygromas are strongly associated with Turner syndrome (usually 45 XO), which causes an abnormal phenotype in affected girls.5
Age
Cystic hygromas can be discovered before birth or in the neonatal period. Occasionally, the cystic hygroma may not be discovered until the patient is older.
Related Medscape topic:
Resource Center Neonatal Medicine
Anatomy
In cystic hygroma, cavernous lymphatic spaces communicate and grow to form large cysts that can infiltrate the surrounding tissue.
Presentation
Fetal cystic hygromas have almost a 50% association with chromosomal disorders, such as aneuploidy. Cystic hygroma is strongly associated with Turner syndrome (predominantly a 45 XO karyotype), trisomy 21 (Down syndrome), trisomy 18 (Edwards syndrome), and Noonan syndrome.1,4,5,8,9,10 Some cystic hygromas can occur in otherwise healthy fetuses and babies. In such patients, postnatal treatment is aimed at improved cosmesis or the alleviation of mechanical complications. Occasionally, cystic hygromas can become large and extend into the mediastinum, axillae, mouth, and chest. Occasionally, they occur exclusively in those areas. As with other fetal anomalies, larger hygromas may be detected at an earlier point in gestation.11
Some suggest that the prenatal diagnosis of cystic hygromas is particularly aided by transvaginal ultrasonography (US). In fact, the condition is most often diagnosed by using prenatal US, and the findings can be striking and unmistakable. Findings include large cystic structures, usually with multiple septa related to the back of the neck of the fetus. Cystic hygromas have been associated with oligohydramnios, but this is not a typical finding. Some patients can have features of hydrops.
Fetal cystic hygroma is a part of a continuum of pathology, and varying degrees of involvement are described, each with its own incidence of chromosomal involvement. The stages, and their risk of chromosomal abnormality, are as follows:
- Localized nuchal fluid - 12% risk
- Diffuse nuchal translucency - 23% risk
- Cystic hygroma - 50% risk
- Fetal hydrops - 78% risk
Although most hygromas (75%) involve the neck, they can also affect other sites, including the axillae (20%), mediastinum, retroperitoneum, abdominal viscera, groin, bones, and scrotum (5%).
First-trimester findings can be subtle, and only increased nuchal translucency may be evident.3 These masses may continue to grow into typical hygromas. Rarely, lymphatic-venous communications can develop later in the prenatal period, and the hygromas then resolve. Many believe that the webbed neck of patients with Turner syndrome is the residual material from a resorbed cystic hygroma.
Morbidity and mortality appear to be more common among those fetuses with multilocularity or septa in their cystic hygromas. This observation may be indicative of true cystic hygromas rather than of simulators. In one report, the authors indicated that nonseptate cystic hygromas were transient in 98% of cases, whereas septate cystic hygromas were transient in only 44% of cases. In this same series, 72% of fetuses with septate cystic hygromas had aneuploidy.7
Cystic hygromas found in a purely anterior location on the neck are usually not related to cystic hygromas associated with aneuploidy and death. They have a better prognosis, and many resolve spontaneously.
Preferred Examination
US is the modality of choice for diagnosing fetal cystic hygromas.12 US is readily available, noninvasive, and used extensively in pregnancy for fetal monitoring and diagnosis.
Magnetic resonance imaging (MRI) requires a long acquisition time, making it impractical unless special protocols are used. MRI is also expensive and not readily available in all settings.
Computed tomography (CT) scanning uses ionizing radiation and is contraindicated in pregnancy unless overriding considerations are involved.
Plain radiography also uses ionizing radiation and is contraindicated. If plain radiographs are used, the findings are not helpful because this condition affects the soft tissue, and the image is unlikely to have good contrast.
Limitations of Techniques
In the diagnosis of fetal cystic hygromas, US is considered the modality of choice. Fetal positioning, maternal body habitus, and operator dependence can make the diagnosis difficult at times. The diagnosis can be missed, even with large fetal cystic hygromas, when severe oligohydramnios is present; the hygromas can be mistaken for pockets of amniotic fluid.
Plain radiography is contraindicated because it uses ionizing radiation. In addition, because the pathology is limited to the soft tissue, it is not expected that radiographs would be helpful.
CT scanning also involves ionizing radiation, but this modality can provide better resolution in select patients.
MRI can be used to assess the extent of infiltration of the cysts into the surrounding structures, but special fast MRI sequences must be used to overcome normal fetal movement, which obviously cannot be controlled.
Differential Diagnoses
Branchial Cleft Cysts
Encephalocele
Other Problems to Be Considered
Anterior cystic hygroma
Laryngocele
Posterior encephalocele
Cervical meningocele or meningomyelocele
Transient cervical cyst
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References
Charasson T, Ko-Kivok-Yun P, Martin F, et al. [Screening for trisomy 21 by measuring nuchal translucency during the first trimester of pregnancy]. J Gynecol Obstet Biol Reprod (Paris). 1997;26(7):671-8. [Medline]. [Full Text].
Jenderny J, Schmidt W, Hecher K, et al. Increased nuchal translucency, hydrops fetalis or hygroma colli. A new test strategy for early fetal aneuploidy detection. Fetal Diagn Ther. Jul-Aug 2001;16(4):211-4. [Medline].
[Best Evidence] Graesslin O, Derniaux E, Alanio E, et al. Characteristics and outcome of fetal cystic hygroma diagnosed in the first trimester. Acta Obstet Gynecol Scand. 2007;86(12):1442-6. [Medline].
Estroff JA. Nuchal translucency in Turner syndrome. In: Cohen HL, Sivit CJ, eds. Fetal and Pediatric Ultrasound. New York, NY: McGraw-Hill; 2001:36-8.
Vaknin Z, Reish O, Ben-Ami I, et al. Prenatal diagnosis of sex chromosome abnormalities: the 8-year experience of a single medical center. Fetal Diagn Ther. 2008;23(1):76-81. [Medline].
Gedikbasi A, Gul A, Sargin A, et al. Cystic hygroma and lymphangioma: associated findings, perinatal outcome and prognostic factors in live-born infants. Arch Gynecol Obstet. Nov 2007;276(5):491-8. [Medline].
Bronshtein M, Bar-Hava I, Blumenfeld I, et al. The difference between septated and nonseptated nuchal cystic hygroma in the early second trimester. Obstet Gynecol. May 1993;81(5 pt 1):683-7. [Medline].
Byrne J, Blanc WA, Warburton D, et al. The significance of cystic hygroma in fetuses. Hum Pathol. Jan 1984;15(1):61-7. [Medline].
Zarabi M, Mieckowski GC, Mazer J. Cystic hygroma associated with Noonan''s syndrome. J Clin Ultrasound. Sep 1983;11(7):398-400. [Medline].
Celentano C, Prefumo F, Iezzi I, et al. Cystic hygroma and mid-trimester maternal serum screening. J Med Screen. 2007;14(3):109-12. [Medline].
Dallapiccola B, Zelante L, Perla G, et al. Prenatal diagnosis of recurrence of cystic hygroma with normal chromosomes. Prenat Diagn. Sep-Oct 1984;4(5):383-6. [Medline].
Chervenak FA, Isaacson G, Blakemore KJ, et al. Fetal cystic hygroma. Cause and natural history. N Engl J Med. Oct 6 1983;309(14):822-5. [Medline].
Rasidaki M, Sifakis S, Vardaki E, et al. Prenatal diagnosis of a fetal chest wall cystic lymphangioma using ultrasonography and MRI: a case report with literature review. Fetal Diagn Ther. Nov-Dec; 2005;20(6):504-7. [Medline].
Benacerraf BR, Frigoletto FD Jr. Prenatal sonographic diagnosis of isolated congenital cystic hygroma, unassociated with lymphedema or other morphologic abnormality. J Ultrasound Med. Feb 1987;6(2):63-6. [Medline].
Cohen HL. Ascites and pleural effusion in hydrops. In: Cohen HL, Sivit CJ, eds. Fetal and Pediatric Ultrasound. New York, NY: McGraw-Hill; 2001:79-82.
Mota R, Ramalho C, Monteiro J, et al. Evolving indications for the EXIT procedure: the usefulness of combining ultrasound and fetal MRI. Fetal Diagn Ther. 2007;22(2):107-11. [Medline].
Garden AS, Benzie RJ, Miskin M, et al. Fetal cystic hygroma colli: antenatal diagnosis, significance, and management. Am J Obstet Gynecol. Feb 1986;154(2):221-5. [Medline].
Hoffman-Tretin J, Koenigsberg M, Ziprkowski M. Antenatal demonstration of axillary cystic hygroma. J Ultrasound Med. Apr 1988;7(4):233-5. [Medline].
Lyngbye T, Haugaard L, Klebe JG. Antenatal sonographic diagnoses of giant cystic hygroma of the neck. A problem for the clinician. Acta Obstet Gynecol Scand. 1986;65(8):873-5. [Medline].
Marchese C, Savin E, Dragone E, et al. Cystic hygroma: prenatal diagnosis and genetic counselling. Prenat Diagn. May-Jun 1985;5(3):221-7. [Medline].
Miller JM, Taboada JC. Cystic hygroma colli in an adult. Johns Hopkins Med J. Apr 1974;134(4):233-6. [Medline].
Montinari M, Papadia J, Guido G, et al. [On cystic hygroma of the neck in infants. Considerations on 5 cases]. G Ital Chir. Sep 1965;21(5):577-95. [Medline].
Pfeiffer KH, Bohm HR, Metzger H. [Prenatal diagnosis of congenital cystic neck hygroma. Comparison of sonographic and computed tomography findings]. Geburtshilfe Frauenheilkd. Jun 1983;43(6):394-8. [Medline].
Phillips HE, McGahan JP. Intrauterine fetal cystic hygromas: sonographic detection. AJR Am J Roentgenol. Apr 1981;136(4):799-802. [Medline].
Further Reading
Keywords
cystic hygroma, cystic lymphangiomas, familial nuchal blebs, FCH, fetal cystic hygromas, cystic hygroma colli, jugular lymphatic obstructive sequences, moist tumors, lymphatic malformations, Turner syndrome, Turner's syndrome, trisomy 21, Down syndrome, Down's syndrome, trisomy 18, Edwards syndrome, Noonan syndrome, Noonan's syndrome
