Extracellular matrix changes in congenital hypertrophic pyloric stenosis

In pyloric stenosis, investigations of the histological pathology have concentrated on neuromuscular changes. These have shown a decrease in the innervation of the hypertrophied circular muscle and variable changes in the myenteric plexus. This study shows that the extracellular matrix (ECM) molecules have characteristic patterns in pyloric stenosis: chondroitin sulfate was markedly increased, with smaller increases in fibronectin and laminin. The increase in chondroitin sulfate was present in patients who were only several weeks old, with a short history, and in whom there was minimal circular muscle hypertrophy, and therefore was an early feature. It is not possible to ascribe aetiological significance to the increase in ECM molecules; nevertheless, the increase of chondroitin sulfate is the most likely explanation for the characteristic cartilaginous quality of the pyloric swelling.