ULTRASOUND OF
MECONIUM PERITONITIS
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The diagnosis of meconium peritonitis is usually
made after 20 weeks gestational age as bowel peristalsis, which is essential to
extrude meconium into the peritoneal cavity, rarely
commences prior to 20 weeks gestation (1).
- Peritoneal calcifications.
- Punctate
calcifications around the periphery of the expected area of the liver and
not in the liver substance itself.
- Calcifications along
the course of the hemidiaphragm.
- Calcifications in the
scrotum of the male fetus (the processus vaginalis connects the scrotal sac to the peritoneal
cavity in late pregnancy) (2).
- Hyperechogenic mass with acoustic shadowing.
- Dilated hyperperistaltic
bowel loops.
- Enlarged fetal abdominal
circumference.
- ± Polyhydramnios.
- ± Ascites.
- Bilateral hydroceles
or swollen vulvae if the processus vaginalis is present.
- Most frequent site of
perforation.
- Meconium
peritonitis without intestinal obstruction is probably secondary to and
ischemic bowel event. "Idiopathic vascular impairment" has been
suggested as the cause (3).
- Fibroadhesive
type.
- Intense fibrotic reaction.
- May be difficult to
image unless it produces bowel obstruction by adhesive bands.
- Generalized Type.
- Peritoneal
calcifications.
- Polyhydramnios
(50%).
- Fetal Ascites (70%).
- Differential
Diagnosis.
- Ruptured hydrometrocolpos.
- Intrahepatic
and venous calcification.
- TORCH infection.
- Calcified meconium
plaques in an obstructed bowel loop.
- Meconium Pseudocyst.
- Adhesions between
bowel loops and omentum which wall off the meconium collection.
- May be extremely large
occupying most of the fetal abdomen.
- Irregular thick-walled
cystic mass ± septations,
calcifications or debris.
- High mortality.
- Differential
Diagnosis.
- Ovarian cyst.
- Choledochal
cyst.
- Mesenteric cyst.
- GI duplication cyst.
- Hydrometrocolpos.
- Urachal
cyst.
- Forouhar
F. Meconium peritonitis: pathology, evolution
and diagnosis. Am J Clin Path 1982;78:208-210.
- Kenney PJ, Spirt BA, Ellis DA et.al.
Scrotal masses caused by meconium peritonitis:
prenatal sonographic diagnosis. Radiology 1985;154:362.
- Tibboel
D, Gaillbard JLJ, Moelenaar
JC. Importance of mesenteric vascular insufficiency in meconium
peritonitis. Hum Pathol 1986;17:411-416.