Megacystis microcolon intestinal hypoperistalsis syndrome overlapping prune belly syndrome

Abstract Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) is a rare congenital visceral myopathy. We experienced a case of an infant with MMIHS with prune belly syndrome (PBS). A pregnant woman was transferred at 16 gestational weeks for a cyst in the fetal bladder. Fetal bladder punctures and a vesicoamniotic shunting were performed. At 31 gestational weeks, a male preterm infant weighing 2432 g was born. After birth, a urinary catheter was inserted through the hole left by the fetal shunt. Bilateral undescended testicles, a dilated urinary tract, and deficient abdominal wall musculature compatible with PBS were also found. On day 5, microcolon and non-obstructive urethra were diagnosed by radiography. An upper gastrointestinal examination showed no movement of the stomach or intestine. Based on these findings, MMIHS was diagnosed. On day 76, a gastrostomy and ileostomy were performed. The histological findings showed no abnormality of the nerve plexus. The infant died at age 4 months. Fatty degeneration of the liver was found at autopsy. MMIHS has a bad prognosis due to liver dysfunction. Our patient had severe progressive liver dysfunction and symptoms of PBS. We speculate that MMIHS and PBS might fall along the same disease spectrum.