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Rémi Besson

Publications and source records attributed to Rémi Besson.

2 recordsLinked to original sources

[Complexity of pathological interpretation in megacystis-microcolon-intestinal hypoperistalsis syndrome].

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.

Abnormalities, Multiple↗

[Synaptophysin expression abnormalities in Hirschsprung's disease].

Hirschsprung's disease is defined by the congenital absence of ganglion cells in enteric plexuses. Immunostaining of synaptophysin after formalin fixation may be used to identify hyperplasia of nerve fibers and rarefaction of neuromuscular junctions in Hirschsprung's disease. The aim of the study was to evaluate semi-quantitatively the expression of synaptophysin in Hirschsprung's disease, in correlation with morphologic features. This retrospective study included 3 controls, 42 surgical rectal biopsies performed for suspicion of Hirschsprung's disease in children presenting with lower digestive occlusion or severe chronic constipation, including 18 Hirschsprung's disease, and 23 surgical specimens of Hirschsprung's disease. In the absence of Hirschsprung's disease, synaptophysin-positive fibers were numerous but thin in the muscularis mucosae, thin and scarce in the mucosa and submucosa. Neuromuscular junctions were thin and numerous in the muscularis propria. In Hirschsprung's disease, synaptophysin-positive fibers were coarse, and increased in number on each side of the muscularis mucosae. Plexuses were enlarged, weakly stained, and associated in the connective tissue of the muscularis propria with coarse and intensely stained fibers. In conclusion, staining for synaptophysin could be useful to demonstrate abnormalities of enteric innervation in rectal biopsies performed for suspected Hirschsprung's disease in the absence of acetylcholinesterase staining on frozen sections, in transmural biopsies performed for guiding surgery in Hirschsprung's disease, and in cases of extensive Hirschsprung's disease.

Acetylcholinesterase↗