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).