Case of the Week #533

Fabrice Cuillier (Obstetrician), Fabien Ho (Radiologist). Saint-Denis, Reunion island, French southern territories.

Posting Dates: March 24 - April 7, 2021

Case Report: This was an incidental finding at 13 weeks gestation based on the last menstrual period. Previous personal, familial and obstetrical history was non contributory. Our ultrasound examination revealed the following anomalies:

Image 1
Image 2

Video 1
Video 2
Video 3
Video 4

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Images 1 and 2 showed a complex mass with cranial defect, increased NT and maybe a caudal defect as well.

Image 1: Complex mass with cranial defect
Image 2: Complex mass with cranial defect

Videos 1 and 2 (coronal sweep), showed that the mass featured:

  • A few facial bones, without any skull suggesting shared acrania
  • Two spines
  • A possible caudal defect as well
  • A few limbs

Videos 3 and 4 showed two hearts beating side by side.

Video 1: Acrania, and 2 spines forming a cone / \ .
Video 2: Some limbs, and the cord.
Video 3: Coronal sweep showing two hearts beating side by side
Video 4: Axial sweep showing tw hearts beating side by side as well as enlarged nuchal translucency

The patient opted for termination of pregnancy. Macroscopic examination (Image 3) made the final diagnosis of conjoined twins, cephalothoracopagus type, with acrania.

Image 3: The twins have conjoined acrania with two eyes and a conjoined face. There is conjoined, enlarged thorax with two hearts and two upper limbs. The caudal poles are separate without defect, and include two lower limbs per twin, each with 3 segments.

Additional Reading:

Cuillier et al. "History, classification, and two cases of conjoined twins.", Publish date 01/2007.

Please also browse the Articles posted under "Multiple Gestations" and "Twins, conjoined" at

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