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FETAL SPLEEN |
In the fetus, the spleen acts as a hemopoietic center until late in gestation, and produces lymphocytes and monocytes throughout life. The spleen arises as an aggregation of reticular mesenchymal cells in the dorsal mesentery of the stomach during the sixth to seventh weeks, menstrual age. It acquires it's characteristic crescent shape early in the fetal period. The spleen can be identified ultrasonographically after 20 weeks menstrual age (1,2).
- Echogenic organ in the left upper abdomen.
- Echogenicity similar to the liver.
- Either inferior or posterior to the fetal stomach depending on the fetal position.
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1-
Umbilical vein (intrahepatic segment) 2-
Liver 3-
IVC 4-
Descending aorta 5-
Spleen 6-
Fetal stomach |
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- Can be easily visualized if actively sought after.
- Best visualized in the presence of non-immune hydrops.
- Boundaries
- superiorly = diaphragm
- laterally = lower ribs
- medially = stomach
- posteriorly = diaphragm and left kidney
- inferiorly = difficult to delineate sonographically
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Spleen
longitudinal diameter (Table) – Schmidt et.al. 1985
Spleen
sagittal diameter (Table) – Schmidt et.al. 1985
Spleen longitudinal diameter (Graph) – Schmidt et.al.
1985
Spleen sagittal diameter (Graph) – Schmidt et.al. 1985
REFERENCES |
- Aoki S, Hata T, Kitao M. Ultrasonographic assessment of fetal and neonatal spleen. Am J Perinatol 1992;9:361-367.
- Burrig KF. Epithelial (true)
splenic cysts. Am J Surg Pathol 1988;12:275-281.