Meconium Peritonitis

Meconium peritonitis usually results from the perforation of the small bowel in utero. Meconium released into the peritoneal space causes sterile chemical peritonitis which finally resolves with fibrosis and calcifications. The predisposing factors in between 30% to 50% of cases are meconium ileus and cystic fibrosis (as was the case in this patient). In the remainder of the patients, the causes of intestinal obstruction and perforation include atresia, malrotation with volvulus, mesenteric hernias, or congenital bands. Meconium peritonitis usually presents itself after birth. The acute inflammation has resolved by this time leaving behind dense fibrosis, calcifications, and intestinal adhesions. Collections of meconium may be walled off by an area of fibrosis forming meconium pseudocyst. The passage of meconium from inguinal canal to the scrotum may result in meconium periorchitis. Since the fetal gut is not yet colonized with bacteria, the inflammatory reaction in meconium peritonitis is mild. The serosal surface of the small bowel is covered with hemorrhage and fibrinous exudate. There may be foreign body giant cell reaction to fetal squames and calcifications. Image courtesy of Dr. Jean-Christophe Fournet, Paris, France; humpath.com; Used with permission