Fetal tumors of the choroid plexus: is differential diagnosis between papilloma and carcinoma possible?

Fetal choroid plexus tumors are uncommon. The prognosis is widely variable and depends on the histological findings: papilloma or carcinoma. We report a case of prenatal diagnosis of choroid plexus mass detected by ultrasound at 33 weeks of gestation. Prenatal (T1, T2, T2* and diffusion weighted sequences) magnetic resonance imaging (MRI) was used to rule out a hematoma. Follow-up examination by ultrasound and MRI revealed a significant increase in the volume of the mass, suggesting a diagnosis of malignant tumor. A healthy neonate was delivered by Cesarean section at 38 weeks of gestation. Full surgical excision of the tumor was performed at 20 days after delivery and histological analysis revealed a papilloma.

[Prenatal detection of brain anomalies with ultrasonography]. / Détection anténatale des anomalies cérébrales en échographie.

Ultrasound is the first-line imaging study of the fetal brain performed at 12, 22 and 32 weeks of gestation. The very structured evaluation of biometric and morphological data, facilitated by the use of a checklist, ensures a high quality examination. All patients where an anomaly of any key element is suspected should be referred to a center dedicated to prenatal diagnosis for confirmation irrespective of the gestational age. Prenatal diagnosis plays a significant role in France since medical interruption of pregnancy until term is authorized.

[Current events in fetal magnetic resonance]. / Actualité sur l'imagerie par résonance magnétique (IRM) foetale.

The challenge of fetal imaging is crucial in France because of the law allowing termination of pregnancy (TOP) until the end of pregnancy. Fetal MRI is an imaging tool always used after ultrasonography (US). Its indications are pertinent only in relation with a prenatal center. Fetal MRI raises parental anxiety to take into account before and during the examination. To date, cerebral indications are predominant. Fetal brain maturation can be followed with MRI (gyration and myelination) but the optimal moment of a fetal MRI depends on the suspected pathology: the analysis of gyration is possible only by 28 WG, as before this time, the brain surface is smooth; in contrast, the posterior fossa demonstrates a definitive morphology since 20 WG. The ventriculomegaly is the most frequent call sign and includes various entities. MRI can disclose associated abnormalities (heterotopia, gyration, white matter, median line), which can suggest diagnosis and pronosis. A cystic pouch of the posterior fossa must lead to a careful analysis of cerebellum and brainstem to approach the diagnosis. Extracerebral indications become progressively larger and fetal MRI is a useful complementary tool after US to study tumors, particularly cervicothoracic masses. MRI can help to assess the level of bowel obstruction but multiple stenosis and post-stenotic bowel is difficult to evaluate. Fetal MRI can help to evaluate bilateral important pyelocalicial dilatation.