Discussion
Fetal meconium periorchitis is a rare complication that occurs secondary
to meconium peritonitis (1). Fetal bowel perforation
leads to leakage of sterile meconium into the abdominal cavity causing
meconium peritonitis, this leads to passage of meconium through a patent
processus vaginalis resulting in an inflammatory reaction of the soft
tissue around the testicles and MPO (2). Fetal bowel
perforation can be caused by a primary ischemic event, a bowel anomaly
such as atresia or volvulus. In cases of suspected meconium peritonitis,
testing for cystic fibrosis is recommended as it accounts for up to 40%
of cases (3, 4). This is secondary to the abnormal
cystic fibrosis transmembrane conductance regulator (CFTR) resulting in
thick mucus. As a result viscid meconium is formed and can cause
physical obstruction of the terminal ileum (5).
Prenatal diagnosis is challenging and therefore MPO is rarely accurately
diagnosed in utero (1), it is often misdiagnosed as a
hydrocele, inguinal hernia, hematoma, or testicular tumor. The diagnosis
is commonly made in the first few months after birth, however delayed
diagnosis for up to 5 years of life has been reported(6). Neonates usually present with a scrotal swelling,
a large hydrocele, or a scrotal mass palpated on physical exam(7). In some cases, no abnormality is identified at
time of birth (1). Ultrasound findings suggesting
fetal MPO include enlarged scrotum, cystic or solid mass, simple or
complex calcifications that may cast acoustic shadows. Furthermore,
findings supporting a diagnosis of meconium peritonitis include dilated
bowel, intraperitoneal calcifications, and meconium pseudocysts. It is
important to note that leakage of bowel contents overtime could lead to
formation of a pseudocyst as a fibrous wall is formed around the spilled
meconium (3), in a case series and meta-analysis that
examined prenatal ultrasound findings in 244 cases with a diagnosis of
meconium peritonitis, presence of meconium pseudocysts was the strongest
predictor for the need of postnatal surgical
management(8). However, as in the described patient,
meconium pseudocysts are not always visualized prenatally. In a
retrospective study that included 37 cases of meconium peritonitis,
pseudocysts were only identified prenatally in 2
cases(9) . It is crucial to look for small bowel loops
with peristaltic waves within the scrotum as this would be suggestive of
an inguinoscrotal hernia rather than meconium periorchitis(10). MPO diagnosed in the prenatal period tends to
have a good prognosis as intestinal perforation usually will heal before
delivery (11). More importantly the mortality rate
after meconium peritonitis has decreased significantly secondary to
improved fetal diagnostic tools and management (12).
Management of MPO includes conservative and surgical approaches.
In cases where bowel perforation does not heal neonates may develop
bowel distention and an acute abdomen requiring immediate surgery(13). In our case, the neonate needed surgical
intervention on DOL 1 for small bowel resection after suspected
pneumoperitoneum, whereas the pediatric urology team followed a
conservative approach to manage the enlarged scrotum. This emphasizes
the importance of recognizing these cases antenatally to coordinate
delivery at a tertiary care center with a multidisciplinary team (MDT)
approach including Maternal-Fetal Medicine, neonatology, pediatric
urology and pediatric surgery. A MTD is needed for counseling, prompt
intervention and to avoid unnecessary surgery as orchidectomy has been
reported in a benign case of meconium orchitis due to a concern for a
rhabdomyosarcoma (14).