Sodium polystyrene sulphonate (Resonium A) in sorbitol given as an enema or orally to treat hyperkalaemia has been described to induce intestinal necrosis in uraemic patients. We report a case of a premature infant with acute renal insufficiency who developed focal transmural necrosis and perforation of the small intestine after 10 days of administration of calcium polystyrene sulphonatum (Calcium Resonium) in sorbitol by enema and by nasogastric tube. On histological examination of the resected part of the small intestine, numerous strongly basophilic angular crystals of resonium were found in the lumen, in the necrotic wall, as well as in the organized exudate on the peritoneal surface. The crystals showed a strong direct Schiff positivity without preoxidation. They were also stained using PAS, Giemsa, Ziehl-Neelsen, Schmorl, and Gram method. In contrast, the crystals were Congo red and Alcian blue (pH 2.5) negative and non-birefringent. The direct Schiff positivity without preoxidation is virtually pathognomonic for resin crystals in routinely processed tissues. The same crystals were observed in the lumen of the small intestine and in peritoneal adhesions at autopsy. Thus our case provides additional evidence that Resonium A/Calcium Resonium in sorbitol administered as an enema or orally can lead to intestinal necrosis in uraemic patients.

Bioptická laborator Plzen Czech Republic