Inflammatory Pseudotumor Containing Kayexalate Crystals: A Case Report and Review of the Literature

Esophageal Pseudotumor Secondary to Treatment with a Potassium Binder Resin: A Case of Severe Esophagitis Mimicking a Malignancy

Background. Sodium polystyrene sulfonate is a resin used to treat hyperkalemia. Colonic mucosal injury, intestinal ischemia, necrosis, and perforation have been widely reported in the literature, but few cases have reported upper gastrointestinal injury and identify the endoscopic features. Case Presentation. We describe a case of an 83-year-old male, with no prior esophageal symptoms, who developed dysphagia after being treated with sodium polystyrene sulfonate for hyperkalemia. Endoscopic features consistent with severe esophagitis and a mass in the lower esophagus mimicking a malignancy were found, and pathology confirmed resin-induced esophagitis. Discussion. The identification of basophilic crystals in the epithelium with surrounding inflammation is a hallmark of sodium polystyrene sulfonate-induced mucosal injury. Several direct and indirect mechanisms by which SPS may cause mucosal injury have been identified. Prolonged stasis of crystals in the lumen has the potential of developing erosions and ultimately necrosis. The internalization of these crystals to the underlying intestinal mucosa with the combination of the inflammatory response may give an appearance of a luminal mass that can mimic a malignancy. Recognizing the wide-ranging endoscopic findings of resin-induced mucosal injury in the esophagus is fundamental to consider a potential side effect of sodium polystyrene sulfonate. The use of this resin should be avoided in patients with suspected esophageal motility disorder.

Lower Gastrointestinal Bleeding Associated With Sodium Polystyrene Sulfonate Use

Sodium polystyrene sulfonate (kayexalate) is a cation-exchange resin widely used in the management of hyperkalemia. Gastrointestinal adverse events are uncommon; symptoms are nonspecific, and mucosal injury can range from mild ulceration to bowel perforation. An 81-year-old man was admitted because of decompensation of cirrhosis with acute kidney injury and hyperkalemia, treated with sodium polystyrene sulfonate. During admission, he presented multiple episodes of hematochezia, accompanied by tachycardia and hemoglobin drop. Colonoscopy revealed colonic ulceration, and histopathological findings were compatible with ulceration due to kayexalate injury. Despite rare, the widespread use of sodium polystyrene sulfonate puts a large population at risk of serious complications related to its use.

The Successful Treatment of Sodium Polystyrene Sulfonate-induced Enteritis Diagnosed by Small Bowel Endoscopy

Sodium polystyrene sulfonate (SPS: Kayexalate^®) is an ion-exchange resin used to treat hyperkalemia in patients with chronic kidney disease. It is known that this resin sometimes causes colonic necrosis and perforation, but there are few reports about small bowel necrosis associated with SPS. We herein report the case of a patient who developed SPS-induced small bowel necrosis, which was diagnosed based on the examination of a small bowel endoscopic biopsy specimen. The SPS-induced small bowel necrosis was resistant to conservative treatment including the cessation of SPS, and finally required surgical bowel resection.

Resin-Induced Colonic Pseudotumor: Rare Complication from Chronic Use of Potassium Binders in a Hemodialysis Patient

Potassium-binding resins are widely used in the treatment of hyperkalemia, mostly in the acute setting. Gastrointestinal adverse events, although reported, are not frequently seen due to its short course of use. This report describes a case involving an end-stage renal disease patient on hemodialysis who developed a colonic mass after being on sodium polystyrene sulfonate chronically for persistent hyperkalemia. Gastrointestinal symptoms developed late during the treatment rather than early as reported previously in the literature. This mass was mistaken for a carcinomatous lesion, which initiated an extensive work-up as well as hospitalization that nearly resulted in a subtotal colectomy.