CEUSP. Valencia. Venezuela

Case report

Following images show a case of fetal abdominal tumor first time observed at 22 weeks of pregnancy of a 23-year-old woman. Her previous ultrasonographic exams were reported to be normal.

The tumor was slightly hypoechoic, homogeneous, and well bordered by a thin hyperechoic layer. The mass was located in posterior meso-epigastric region of the fetal abdomen. The tumor had been surrounding and deviating the course of the descending aorta. Its vasculature was poor, but increased systolic and diastolic velocities were observed within the supplying vessels.

The patient was scanned again at 23, 25, and 26 weeks. The tumor had slightly increased in size reaching 45 mm in its largest diameter. Myocardial hypertrophy, hydrothorax, and ascites had also been present. The pregnancy was interrupted and the pathological study confirmed the presence of the tumorous mass originating from the psoas muscles and infiltrating vertebral bodies, diaphragm, aorta and esophagus. Final histopathological diagnosis was rhabdomyosarcoma of the psoas muscles.

Images 1, 2: 22 weeks of gestation; the image 1 shows transverse scan of the fetal abdomen at the level of the stomach - well bordered mass in front of the spine containing the descending aorta can be seen. The image 2 shows coronal color Doppler scan of the abdomen depicting deviated course of the aorta within the tumorous mass.

Images 3, 4: 22 weeks of gestation; the image 3 shows deviated course of the inferior vena cava caused by the tumor; the image 4 shows color Doppler image of divergent course of the descending aorta and inferior vena cava within the tumor.

Image 5: 22 weeks of gestation; normal flow within the ductus venosus.

Images 6, 7: 23 weeks of gestation; coronal and transverse views of the tumor located in front of the spine at the level of the fetal stomach. Size of the tumor in the coronal plane was 30 x 29 mm.

Images 8, 9: 23 weeks of gestation; color Doppler longitudinal views of the abdominal tumor showing it vascular supply and "S-shaped" deviation of the aorta.

Images 10, 11: 25 weeks of gestation; transverse and coronal views of the tumor located in front of the spine at the level of the fetal stomach. Size of the tumor had reached 38 x 28 mm in transverse plane, and 36 x 44 mm in coronal plane.

Image 12: 25 weeks of gestation; the image shows various Doppler velocities within the vessels supplying the tumor - inlet (30cm/s), middle (120-130 cm/s), and outlet (213 cm/s).

Images 13, 14, 15, 16, and 17: 25 weeks of gestation; MRI images showing the fetal tumor located in front of the spine at the level of the fetal stomach.

Images 18, 19: 26 weeks of gestation; the image 18 shows transverse scan of the fetal abdomen with ascites and tumorous mass in front of the spine 45 x 36 mm; the image 19 shows cardiac hypertrophy and hydrothorax.

Images 20, 21, 23: 23 weeks of gestation; autopsy images of the fetus with tumorous mass in front of the spine at the level of the fetal stomach. The image 24 shows the tumor after its resection.

Images 24, 25, 26, and 27: Histopathological images showing the structure of rhabdomyosarcoma.