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PSEUDOCYSTS OF THE
UMBILICAL CORD |
A pseudocyst is a cavity that forms from liquefaction or mucoid degeneration of Wharton's jelly. It has no epithelial lining and its etiology is unknown. Large masses of mucus in the umbilical cord are usually associated with hemangiomas of the umbilical cord, also called angiomyxomas. The large pseudocysts are probably fluid collections produced by this tumor. The fluid cannot escape through the thick epithelium of the umbilical cord and appears as a large cystic mass (1).
Bergman 1962 (2); 2 cases - one stillborn and one alive and normal.
Iaccarino 1986 (3); 7cm cyst compressing the umbilical vessels and IUGR. The
pregnancy was terminated.
UMBILICAL CORD CYSTS AND ANEUPLOIDY |
Link to Umbilical Cord
Pseudocysts and Aneuploidy
ULTRASOUND |
- Two thirds are at the placental end / one third are at the fetal end (4).
- May enlarge as the pregnancy progresses (largest reported cyst = 25 cm)(5)
- Sonographic appearance varies widely in utero:
- Large cyst-like mass (6).
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- Multiple cysts close to a localized thickening of Wharton's jelly (6). All these cases were associated with chromosomal aneuploidy in one series (trisomy 18 and 13) (6).
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Trisomy 18: ·
Multiple umbilical cord pseudocysts. ·
Two vessel cord |
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- Single or multiple, large or small. Regardless of their sonographic appearance in utero, they have a strong association with chromosomal anomalies and structural defects (6).
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Umbilical cord pseudocyst at 13 weeks of gestation |
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- Angiomatous segment.
- 1-9 cm.
- Echogenic mass adjacent to large cystic component. Associated vascular changes in the cord may sometimes be observed with color doppler. One or more of the umbilical vessels may be narrowed (5,7).
DIFFERENTIAL DIAGNOSIS |
True and pseudocysts of the cord have similar appearances; true cysts are
usually associated with anomalies of the umbilicus and / or bladder such as
omphalocele or patent urachus.
MANAGEMENT |
- Detection of a pseudocyst prior to 24 weeks gestation is an indication for fetal karyotyping.
- After 24 weeks an isolated pseudocyst is not an indication for karyotyping. Based on current literature the risk of trisomy 18 in a fetus with no other sonographic findings after this gestational age is extremely low (8-10). In two large series (involving 62 cases of trisomy 18), all 24 cases examined after 24 weeks had sonographically detected abnormalities (7,9). Only 27 out of 38 (71%) had sonographically detected abnormalities when scanned prior to 24 weeks (8, 10).
- After 24 weeks a pseudocyst associated with other anomalies is an indication for karyotyping (11).
REFERENCES |
- Harp J, Rouse GA, De Lange M. Sonographic prenatal diagnosis of allantoic cyst. JDMS 1992;8:28-32.
- Bergman P, Lundin P, Malmstrom T. Mucoid degeneration of Wharton's jelly: An umbilical cord anomaly threatening fetal life. Acta Obstet Gynecol Scand 1961;40:372.
- Iaccarino M, Baldi F, Persico O et.al. Ultrasonographic and pathologic study of mucoid degeneration of the umbilical cord. J Clin Ultrasound 1986;15:127.
- Heifetz SA, Rueda-Pedraza ME. Hemangiomas of the umbilical cord. Pediatr Pathol 1983;1:385-398.
- Yavner DL, Redline RW. Angiomyxoma of the umbilical cord with massive cystic degeneration of Wharton's jelly. Arch Pathol Lab Med 1989;113:935-937.
- Sepulveda W, Gutierrez J, Sanchez J et.al. Pseudocysts of the umbilical cord: Prenatal sonographic appearance and clinical significance. Obstetrics and Gynecology 1999;93:378-381.
- Jaunianx E, Campbell S, Vyes S. The use of color doppler imaging for prenatal diagnosis of umbilical cord anomalies: report of three cases. Am J Obstet Gynecol 1989;161:1195-1197.
- Benacerraf BR, Miller Wa, Frigoletto FD. Sonographic detection of fetuses with trisomy 13 and 18: accuracy and limitations. Am J Obstet Gynecol 1988;158:404-409.
- Benacerraf BR. Prenatal sonography of autosomal trisomies. Ultrasound Obstet Gynecol 1991;1:66-75.
- Nyberg DA, Kramer D, Resta RG et.al. prenatal sonographic findings of trisomy 18: a review of 47 cases. J Ultrasound Med 1993;12:103-113.
- Sepulveda W, Pryde PG, Greb AE et.al. Prenatal diagnosis of umbilical cord pseudocyst. Ultrasound Obstet Gynecol 1994;4:147-150.