Open Access

Bilateral neck cysts as an isolated sonographic finding in the antenatal detection of fetal aneuploidy: a case report

  • Khalil Abi-Nader1,
  • Elisa Filippi1Email author,
  • Pranav P Pandya1 and
  • Elisabeth Peregrine1
Cases Journal20092:8322

https://doi.org/10.4076/1757-1626-2-8322

Received: 13 November 2008

Accepted: 16 June 2009

Published: 6 July 2009

Abstract

Isolated fetal lateral neck cysts can represent a cystic hygroma or a developmental remnant cyst. In the absence of an increased nuchal translucency or associated malformations the risk of aneuploidy has been considered negligible. Still, dysmorphology in aneuploid fetuses might not be evident except at a later stage. We report on a case of isolated fetal bilateral neck cysts where aneuploidy was suspected and confirmed despite the lack of associated morphologic abnormalities.

Case presentation

A 34 year old middle eastern lady with a spontaneous conception presented at 13 weeks of gestation for a routine 1st trimester ultrasound and screening. Her booking weight was 79 kg and her height 165 cm. She was a housewife with three previous uncomplicated pregnancies delivered vaginally. She was on no medication except for iron supplement. The past medical and surgical history was unremarkable and the patient was neither a smoker nor an alcohol drinker. The family history of her partner and herself was unremarkable as well.

On 1st trimester ultrasound, the fetus was noted to have bilateral anterolateral neck cysts around 5 × 5 mm in size (Figures 1 and 2) suggestive of either 'non-septated cystic hygromas' which are congenital malformations of the lymphatic system characterized by fluid-filled jugular lymphatic sacs of the fetal neck [1, 2] or, the much rarer bilateral branchial cleft cysts. No other abnormalities were noted and the nuchal translucency measured 2.3 mm. The patient was counselled for the high possibility of spontaneous regression and good fetal outcome awaiting the results of the integrated 1st trimester screening test. At 16 weeks, integrated screening gave a 1 in 2 risk for trisomy 18 and therefore fetal ultrasonograpy was repeated. The fetal growth and amniotic fluid volume were normal and the bilateral neck cysts were stable in size. No other abnormalities could be detected despite a careful sonographic assessment and an amniocentesis for fetal karyotyping was offered and accepted. PCR on the amniotic fluid revealed trisomy 18 which was confirmed by cytogenetic analysis.
Figure 1

Coronal section: A coronal ultrasound section of the fetal head and neck region at 13 weeks of gestation shows bilateral cysts in the middle-half of the neck.

Figure 2

Trans-axial section: The same cysts seen in Figure 1are shown here in cross section using ultrasound. The cysts are located anterolaterally in the neck and the posterior nuchal region looks normal.

Figure 3

Post-mortem appearance of the fetus: The external findings are low-set ears, legs fixed in extension and clenched fists. The scalp was damaged during the delivery.

The couple decided to opt for termination of pregnancy which was completed medically at 17+4 weeks with no complications. Pathologic examination of the fetus revealed a dysmorphic face with low-set ears, both legs fixed in extension and clenched fists. At autopsy the neck cysts could not be identified, but there had been considerable trauma to the scalp during delivery. Internally the kidneys and adrenals were of normal size and shape but there was dysplasia on microscopy. There was abnormal placental villous morphology, of a pattern consistent with aneuploidy. There were no internal gross structural anomalies that had been missed on the scan.

Discussion

The differential diagnosis of fetal anterolateral neck cysts includes dilated jugular lymphatics defining a cystic hygroma [1], the presence of branchial cleft cysts, and a thyroid cyst [3]. Non-septated cystic hygromas are unilateral or bilateral, simple appearing cysts that are located in the antero-lateral cervical region [4]. Bilateral branchial cleft cysts are extremely rare representing only 1% of branchial cleft cysts [5] and antenatal diagnosis is barely reported for the unilateral cases [6]. Thyroid cysts on the other hand, usually occur in association with maternal thyrotoxicosis [3].

Antenatally detected isolated bilateral neck cysts without an increase in nuchal translucency have been linked to physiologic delay in jugular lymphatic development leading to spontaneous resolution before 17 weeks of gestation [2]. While Bronstein et al. noted a 5% aneuploidy rate in the presence of this finding, cases with trisomy 18 or 21 had additional associated abnormalities [7]. Other investigators did not find an association between fetal aneuploidy and islolated lateral neck cysts in the absence of an increased nuchal translucency [1, 2, 8].

This case clearly indicates that the presence of isolated fetal lateral neck cysts in the first trimester and early second trimester should not be dismissed directly as a variant of normal development. Close follow up should be instituted as structural abnormalities may become apparent at a slightly later gestation [9]. Invasive testing for fetal karyotype should be considered. If the neck cysts resolve before mid-gestation and no additional abnormalities are detected on subsequent scans, the outlook for the pregnancy is excellent [7].

Consent

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent form is available for review of the Editor-in-Chief of this journal.

Abbreviation

PCR: 

Polymerase chain reaction.

Declarations

Acknowledgements

Authors want to thank Dr Rosemary Scott, Consultant Histopathologist and Honorary Senior Lecturer at University College London Hospital.

Authors’ Affiliations

(1)
Fetal Medicine Unit, The Elizabeth Garrett Anderson Obstetric Hospital, Institute for Women's Health, University College London Hospitals NHS Trust

References

  1. Kharrat R, Yamamoto M, Roume J, Couderc S, Vialard F, Hillion Y, Ville Y: Karyotype and outcome of fetuses diagnosed with cystic hygroma in the first trimester in relation to nuchal translucency thickness. Prenat Diagn. 2006, 26: 369-372. 10.1002/pd.1423.View ArticlePubMedGoogle Scholar
  2. Achiron R, Yagel S, Weissman A, Lipitz S, Mashiach S, Goldman B: Fetal lateral neck cysts: early second-trimester transvaginal diagnosis, natural history and clinical significance. Ultrasound Obstet Gynecol. 1995, 6: 396-399. 10.1046/j.1469-0705.1995.06060396.x.View ArticlePubMedGoogle Scholar
  3. Suchet IB: Ultrasonography of the fetal neck in the second and third trimesters. Part 3. Anomalies of the anterior and anterolateral nuchal region. Can Assoc Radiol J. 1995, 46: 426-433.PubMedGoogle Scholar
  4. Rotmensch S, Celentano C, Sadan O, Liberati M, Lev D, Glezerman M: Familial occurrence of isolated nonseptated nuchal cystic hygromata in midtrimester of pregnancy. Prenat Diagn. 2004, 24: 260-264. 10.1002/pd.849.View ArticlePubMedGoogle Scholar
  5. Doshi J, Anari S: Branchial cyst side predilection: fact or fiction?. Ann Otol Rhinol Laryngol. 2007, 116: 112-114.View ArticlePubMedGoogle Scholar
  6. Tsai PY, Chang CH, Chang FM: Prenatal imaging of the fetal branchial cleft cyst by three-dimensional ultrasound. Prenat Diagn. 2003, 23: 605-606. 10.1002/pd.639.View ArticlePubMedGoogle Scholar
  7. Bronshtein M, Bar-Hava I, Blumenfeld I, Bejar J, Toder V, Blumenfeld Z: The difference between septated and nonseptated nuchal cystic hygroma in the early second trimester. Obstet Gynecol. 1993, 81: 683-687.PubMedGoogle Scholar
  8. Sharony R, Tepper R, Fejgin M: Fetal lateral neck cysts: the significance of associated findings. Prenat Diagn. 2005, 25: 507-510. 10.1002/pd.1161.View ArticlePubMedGoogle Scholar
  9. Bar-Hava I, Bronshtein M, Drugan A: Changing dysmorphology of trisomy 18 during midtrimester. Fetal Diagn Ther. 1993, 8: 171-174. 10.1159/000263819.View ArticlePubMedGoogle Scholar

Copyright

© Abi-Nader et al.; licensee Cases Network Ltd. licensee BioMed Central Ltd. 2009

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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