Chorionic bump in ultrasound of the first trimester: Report of a case and bibliographic review

Abstract

Background: Chorionic bump involves the gestational sac and can be visualized in first trimester ultrasound. It is described as an irregular convexity that protrudes towards the gestational sac and corresponds to the formation of a hematoma on choriodecidual surface.
 Objective: This is a clinical case reported in a second level hospital. An updated search was carried out on the topic of timely diagnosis of chorionic bump.
 Case Report: A round echogenic mass protruding from the choriodecidual surface, measuring 17.3 x 16.5 x 19.1mm, was identified during a transvaginal examination at 8 weeks' gestation. Uterine cavity with an irregular Gestational Sac with a mean diameter of 29.9mm with poor decidual reaction, observing the amnion inside without evidence of an embryonic pole and a 2.3mm yolk sac. The pregnancy was not viable.
 Discussion: Etiopathogenesis remains unclear. This case demonstrates that a chorionic bump can be considered a poor prognostic finding in ecosonogram.
 Conclusion: "Chorionic Bump" is a phenomenon little investigated in ultrasound. The etiology is still unknown. When it is identified, it can be associated with a poor prognostic finding. The most important task for the sonographer is to know how to identify and differentiate it correctly from an early embryonic death.