The chorionic bump associated with acrania – case report

Abstract

The chorionic bump is a rare abnormality of the gestational sac, presenting as a convex bulge from the choriodecidual surface into the sac, correlated with poor prognosis for the pregnancy We report a case of a 36-year-old pregnant woman, with a history of spontaneous abortion, who presented for an early scan a 6 weeks and 4 days of gestation. The pregnancy was spontaneous and unplanned. The patient conceived in less than 3 months after discontinuing oral contraceptives. No folic acid was taken before or in the pregnancy An ultrasound scan revealed a chorionic bump with a hypoechoic center and echogenic border, measuring 18.3 x 14.7 x 21.9 mm. No motion within the chorionic bump was detected upon color and power Doppler examination. The second scan was performed a week later at 7+4 wks. The chorionic bump had not changed in terms of size and sonographic appearance. An acranial fetus of CRL 45.5 mm was diagnosed at 11 + 2 wks. The concentration of free beta-hCG was 17.2 IU/L, corresponding to 0.37 MoM and PAPP-A levels were 1.31 IU/L, corresponding to 0.82 MoM. After counseling the patient opted for termination of pregnancy Very few cases of chorionic bumps have been described so far and, to the best of our knowledge, its coexistence with neural tube defects has been reported for the first time. We postulate a possibility of an underlying pathological mechanism for such coexistence. The chorionic bump is a focal convex bulge with irregular borders, protruding from the choriodecidual surface into the gestational sac and with different degrees of echogenicity usually a hypoechoic middle and echogenic border The chorionic bump might represent the following: a hematoma, an area of hemorrhage, a non-embryonic gestation, or a demise of an embryo in a twin pregnancy The presence of the bump is associated with a four-fold increase in the spontaneous abortion rate as compared with the general population. Decreased folate levels increase the incidence of neural tube defects. Oxidative stress resulting from folic acid deficiency may be responsible for neural tube defects through impairment of factors inhibiting apoptosis in the neuroepithelium. Fetuses with neural tube defects are at an increased risk of being aborted spontaneously Furthermore, women who deliver children with neural tube defects frequently have a history of miscarriage. Our patient did not take any folic acid and also had a history of spontaneous miscarriage. In the case we herein presented, the coexistence of acrania and placental pathology could be attributed to folate deficiency Such coexistence is described for the first time and could be accidental, but there is possible theoretical association between these two pathologies.