Catherine Fallet-Bianco
Neuropathologist (CHU Sainte-Justine)
Full Clinician Professor (Université de Montréal)
Certification in Neurology, Fetal Pathology and Dysmorphology in genetics
Clinical and research interest are in Developmental and Pediatric Neuropathology, Neuropathology of epilepsy


Marie Denis-Musquer1, Madeleine Joubert1, Catherine Fallet-Bianco2 1-Laboratory of Pathology, CHU
DE Nantes, Nantes, 44093, France 2-Départment of Pathology, Hôpital Sainte-Justine- Université de Montréal, QC, Canada


Clinical History: A 32-year-old woman, primigravida, is referred to the Prenatal Diagnostic Center for a second trimester evaluation. There was no significant family history or parental consanguinity. At 20 WG, ultrasonography revealed cerebellar hypoplasia, confirmed by the control US at 25w2d, which also showed minor dysmorphic features. At 28w2d, in addition to the cerebellar hypoplasia, which affects both hemispheres, US shows a median hyperechogenic image erasing the V4 and a hypoplastic and flat brainstem. CGH-Array showed no abnormalities. This male fetus was delivered at 30w2d of gestation.
Autopsy finding: Autopsy examination showed a male fetus with normal biometric parameters, minor dysmorphic features, no skeletal or visceral lesion or malformation. Brain weight: 220 g (75th percentile according Guihard-Costa et al. Tables;. Ped Dev Pathol 2002; 5: 559-57). However, brainstem -cerebellum weight was significantly below fifth percentile.

Discussion points

  1. What diagnosis do you suggest on the macroscopic photos?
  2. How would you describe the histological features?
  3. What is (are) the differential diagnosis(es?)
  4. What are the pathogenic mechanisms of these lesions?Genetic hypothesis?