Presentation
Normal first trimester ultrasound of age corresponding to 8 weeks and 5 days
Patient Data
Gender: Unknown
From the case:
Fetal rhombencephalon
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The fetal rhombencephalon is the anechoic structure in the posterior part of the brain. This is a normal appearance at 8-10 weeks, and should not be misinterpreted as a developmental problem.
From the case:
Fetal rhombencephalon
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The blue arrow points to a hypoechoic area in the fetal brain, the normal fetal rhombencephalon.
Case Discussion
The fetal rhombencephalon (also known as the "embryonic rhombencephalon" or "cystic rhombencephalon") is a normal finding in an embryo/fetus at 8-10 weeks of age. It should not be considered a developmental abnormality.