Diagnosis : Rt. Ovarian
cyst with torsion & rupture in female fetus at 35 & 36 weeks
gestational age respectively.
Discussion :
Three physiological cystic
lesions in the fetal abdomen are stomach, gall bladder, urinary bladder.
Other than these three any
cystic lesion in the fetal abdomen is pathological except in female fetus ,
where physiological ovarian follicles or cysts may be noted.
A cyst in the abdomen of
female fetus is most likely ovarian origin due to high level of circulating
maternal estrogen.
A follicular cyst typically
appears as a unilocular , thin-walled cystic mass in the abdomen of a female
fetus.
Importantly, ovarian cysts
do not touch the spine as do cysts of renal origin.
Ovarian cysts in the female
fetus always present in the abdomen rather than in the pelvis because pelvis
is small and fetal ovary is an abdominal organ rather than pelvic organ.
Ovarian cysts may be detected high in upper abdomen.
Majority of fetal ovarian
cysts resolve spontaneously over a time.
Hemorrhage is a relatively
common complication of ovarian cysts due to torsion. Depending up on age of
the bleed, sonographic appearance of cyst altered. These cysts may appear
as diffuse echogenic material, diffuse echoes with visible fibrin strands,
retracting thrombus, and fluid-fluid levels.
Sonographic observation of cyst
hemorrhage is made after the torsion has occurred and any opportunity for
operative salvage of the ovary has passed, emergency obstetric intervention is
not appropriate.
Ovarian cysts usually have a
benign course – regress spontaneously at most require surgical resection after
birth.
Ovarian cysts should have a
relatively long period of post natal follow up. Surgical removal is considered
only for those rare cysts that do not reduce in size after birth, when there
is no further estrogen stimulation .
Prenatal torsed ovary may
undergo atrophy post natally.
A variety of other abdominal
cysts should be considered in differential diagnosis
Three are relatively common :
-
Meconium pseudo cyst
– can occur anywhere in
the abdomen have invariably calcifications in their walls.
-
Choledochal cyst
– seen adjacent to the
inferior surface of right hepatic lobe.
-
Gut
duplication cysts
– low amplitude echoes
with bright sub mucosa is strongly S/o diagnosis
Other rare
cysts are:
-
Mesenteric cysts
– midline in location
always disclose a loop of bowel that creases the cyst or appears to
course directly through the cyst.
-
Meckel’s Diverticular cysts
- found on the right
side of the abdomen
-
Urachal cysts
-
midline in location abuts superior bladder wall.
Reference :
Callen Ultrasonography in Obstetrics and Gynecology 4th
Edition.
Submitted by: Dr.M.Adinarayana Rao,
MD.,RD.
Dr.
D.Prasada Reddy, DMRD.
Dr.G.Gowri Sekhar, DMRD., DNB.
