The chorionic bump: Etiologic insights from two pathologic pregnancies

Abstract

The clinical significance and etiology of the chorionic bump remain unclear. We describe two pregnancies characterized by chorionic bumps, which subsequently were diagnosed with a complete mole and trisomy 18, respectively. We hypothesize that placental pathology, including edema and hydropic villi, may contribute to or cause the sonographic finding of some chorionic bumps. An association between chorionic bumps and aneuploidy awaits future study. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:452-454, 2016.

First‐trimester chorionic bump‐‐Association with fetal aneuploidy in a high‐risk population

“…We recently speculated on an alternative etiology for chorionic bumps associated with aneuploidy, suggesting that chorionic bumps observed in some abnormal pregnancies may be the US manifestation of focal or exaggerated placental pathologic features, particularly villus hydrops and stromal edema. 10 The incidence of a chorionic bump was 23/1,000 pregnancies, notably higher than the reported frequency of 1.5-7/1,000. 1,3 The most likely explanation is that the chorionic bump is more prevalent among pregnancies at increased risk for fetal aneuploidy than in the general obstetric population.…”

Chorionic bump at 11 to 13 weeks' gestation: Prevalence and clinical significance

“…This is true for the general population as well as for patients with a history of infertility treatment. A computerized search of the Pubmed/MEDLINE database using the term “chorionic bump” revealed six larger series describing between eight to 57 cases and eight isolated reports describing one or two cases. Our report adds an additional 23 cases, for a total of 190 cases reported in the English literature.…”

“…Clinical and sonographic evidence, as well as an isolated case of magnetic resonance imaging, suggests that this finding probably represents a hematoma . Histopathologic studies are only available in few cases, with two describing a hematoma and another two, a placental edema and gestational tissue . Nevertheless, sonographic appearance and follow‐up information have shown that the chorionic bump usually resolved by the second trimester, with no harm to the fetus, placenta, or chorioamniotic membranes.…”

“…1 Histopathologic studies are only available in few cases, with two describing a hematoma 3,10 and another two, a placental edema and gestational tissue. 8 Nevertheless, sonographic appearance and follow-up information have shown that the chorionic bump usually resolved by the second trimester, with no harm to the fetus, placenta, or chorioamniotic membranes. However, this lack of histopathological proof does not mean that the chorionic bump should not be considered a high-risk factor for subsequent fetal demise and therefore, sonographic follow-up should be carried out for reassurance.…”

“…This led to the conclusion that this sonographic feature is associated with a guarded prognosis. 1 Until now, the vast majority of cases of chorionic bump have been detected in pregnancies presenting before 11 weeks' gestation, [1][2][3][4][5][6][7][8][9][10][11][12][13][14] with only one report including cases referred for nuchal translucency thickness measurements at 11 to 13 weeks' gestation. 9 However, the latter report was based on pregnancies with available cytogenetic studies, and neither specific clinical details nor pregnancy outcomes were reported.…”