What is the Difference Between Cystic Hygroma and Nuchal Translucency

The key difference between cystic hygroma and nuchal translucency is that cystic hygroma is a type of birth defect that leads to the formation of abnormal growth on an infant’s neck or head, while nuchal translucency is a sonographic appearance of a collection of fluid under the skin behind the neck of the fetus in the first trimester of pregnancy.

Cystic hygroma and nuchal translucency are two structures that appear in the fetal neck. Cystic hygroma is a large single or multilocular fluid-filled abnormal cavity in the posterior region, behind and around the fetal neck. On the other hand, nuchal translucency is a normal fluid-filled space seen behind the fetal neck on ultrasound in the first trimester. It is a normal structure, and its size measurement can be used to detect genetic disorders such as chromosome abnormalities.

CONTENTS

1. Overview and Key Difference
2. What is Cystic Hygroma
3. What is Nuchal Translucency
4. Similarities – Cystic Hygroma and Nuchal Translucency
5. Cystic Hygroma vs Nuchal Translucency in Tabular Form
6. Summary – Cystic Hygroma vs Nuchal Translucency

What is Cystic Hygroma?

Cystic hygroma is a type of birth defect that appears as a sac-like structure in the nuchal region, behind and around the fetal neck. It is an abnormal structure with a thin wall. Most commonly, it occurs in the head and neck area of an infant. Cystic hygroma is also called lymphangioma. As the baby grows in the womb, cystic hygroma can develop from pieces of material that carry fluid and white blood cells. This material is known as embryonic lymphatic tissue. Moreover, after birth, a cystic hygroma normally looks like a soft bulge under the skin of the baby. The cysts cannot be observed until after birth or sometimes until the person is older.

Cystic hygroma can be diagnosed through chest X-ray, ultrasound, and CT scan. Furthermore, the treatment options for cystic hygroma are surgical removal of neck mass, chemotherapy medication, injection of sclerosing medication, radiation therapy, and steroids.

What is Nuchal Translucency?

Nuchal translucency is a sonographic appearance of a collection of fluid under the skin behind the neck of the fetus in the first trimester of pregnancy. This can be used to detect genetic disorders like chromosome abnormalities. A thick nuchal translucency measurement is associated with aneuploidy, other structural anomalies, and cardiac defects. Prenatal screening of nuchal translucency through ultrasonography can detect about 80% of fetuses with trisomy 21 and other major aneuploidies for a false positive rate of 5%. Moreover, a nuchal translucency scan is used as prenatal screening to detect conditions such as Down syndrome, Patau syndrome, Edwards syndrome, and non-genetic body stalk anomaly.

There are two distinct measurements taken in the nuchal translucency: the size of the nuchal translucency and the thickness of the nuchal fold. The size is assessed at the end of the first trimester (between 11 weeks and 3 days and 13 weeks 6 days of pregnancy). The thickness is measured towards the end of the second trimester. Furthermore, as the size of the nuchal translucency increases, the chances of a chromosome abnormality and mortality increase. Nuchal translucency can also help to confirm the accuracy of the pregnancy dates and fetal viability.

What are the Similarities Between Cystic Hygroma and Nuchal Translucency?

• Cystic hygroma and nuchal translucency are two structures that appear in the fetal neck.
• Both are fluid-filled.
• They can be observed during pregnancy.
• Both can be diagnosed via ultrasonography.

What is the Difference Between Cystic Hygroma and Nuchal Translucency?

Cystic hygroma is a type of birth defect that leads to the formation of abnormal growth on an infant’s neck or head. Meanwhile, nuchal translucency is a sonographic appearance of a collection of fluid under the skin behind the neck of the fetus in the first trimester of pregnancy that can be used to detect chromosome abnormalities. Thus, this is the key difference between cystic hygroma and nuchal translucency. Furthermore, cystic hygroma is an abnormal structure, while nuchal translucency is a normal structure.

The below infographic presents the differences between cystic hygroma and nuchal translucency in tabular form for side by side comparison.

Summary – Cystic Hygroma vs Nuchal Translucency

Cystic hygroma and nuchal translucency are two structures that appear in the fetal neck. Cystic hygroma is a type of birth defect that leads to the formation of abnormal growth on an infant’s neck or head, while nuchal translucency is a sonographic appearance of a collection of fluid under the skin behind the neck of the fetus in the first trimester of pregnancy which can be used to detect chromosome abnormalities. So, this is the key difference between cystic hygroma and nuchal translucency.

Reference:

1. “Cystic Hygroma.” Johns Hopkins Medicine, 19 Nov. 2019.
2. “Nuchal Translucency Scan: FMF Certification.” The Fetal Medicine Foundation.

Image Courtesy:

1. “Ultrasound image Cystic Hygroma 20172527109 17F” By © Nevit Dilmen (CC BY-SA 3.0) via Commons Wikimedia
2. “Nuchal translucency” By Wolfgang Moroder – Own work (CC BY-SA 3.0) via Commons Wikimedia