Fetus in fetu

Case contributed by Dr Amr Farouk


3-year-old boy referred to radiology because the clinician palpated an abdominal mass. The initial US showed a large heterogeneous abdominal mass with mixed echogenicity (not shown here). CT of the abdomen was performed for further evaluation.

Patient Data

Age: 3 year old
Gender: Male

CT scan demonstrates a large right hypochondrial mass pushing the liver posteriorly scalloping its anterior surface. The mass is well capsulated with internal mixed fat, soft tissue and bone densities. The bone densities show a near-complete skeleton with an undeveloped brain.


Case Discussion

The differential diagnosis includes a fetus in fetu or a mature or well-organized teratoma.

The presence of axial skeleton with the vertebral axis and an appropriate arrangement of other limbs and organs goes more in favor of a fetus in fetu. Fetus in fetu to be implemented to any structure in which the fetal form has a highly developed organogenesis or to the presence of vertebral axis. Teratoma is an accumulation of pluripotent cells in which there is neither organogenesis nor vertebral segmentation.1

Fetus in fetu never become malignant whereas teratoma is known to become malignant.

Fetus in fetus is rare but should be considered as an alternative to the more common teratoma.

Case courtesy Dr.Maged AbdElRahman Hawanna, Lecturer of diagnostic radiology, faculty of medicine, Cairo University.

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Case information

rID: 57555
Published: 1st Jan 2018
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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