Complexité de l'interprétation anatomopathologique dans le syndrome mégavessie-microcôlon-hypopéristaltisme intestinal

Megacystis-microcolon-intestinal hypoperistalsis syndrome is very rare, and is the most severe of the chronic intestinal pseudoobstructions. Diagnosis is usually made in the neonatal period, is clinical and radiological, and is confirmed by manometric studies. Microscopic abnormalities are variable, inconstant and nonspecific. They involve the smooth muscle more often than the intrinsic innervation of the gut and the bladder. A girl, currently seven years old, presented with megacystis observed on prenatal ultrasound at 21 weeks of gestation. At first, amniotic fluid volume was appropriate for gestational age, and then hydramnios appeared at 30 weeks of gestation. Microcolon was discovered at birth, with microileum, dilatation of the duodenum and proximal jejunum, intestinal malposition, and severe hypoperistalsis of the entire gastrointestinal tract, which indicated enterostomy and total parenteral nutrition from birth. At pathological examination, rectal biopsy and enteric nervous plexuses were normal. There was hypoplasia of the external longitudinal layer of the muscularis propria in the colon and ileum. Cajal cells could not be demonstrated immunohistochemically in the colon. This case highlights the complexity and difficulties of pathological interpretation in this syndrome, and the necessity of a large study of controls at different ages and different levels of the digestive tract and the bladder.