Objective: Medication resins such as Kayexalate and Sevelamer used in the setting of chronic kidney disease for the correction of hyperkalemia and hyperphosphatemia are associated with gastrointestinal mucosal injury. In this study we describe the clinico-pathological features of Resin-induced gastrointestinal mucosal injury highlighting the histo-morphological appearances and differential diagnoses. The aim of this study is to increase the awareness of pathologists and clinicians alike to an under-reported etiology and pattern of intestinal mucosal injury related to medical resin therapy which may at times pose a clinical emergency.

Material and Method: The archives of the Department of Histopathology, Mubarak Al Kabir hospital were analyzed for cases of resin-induced gastrointestinal mucosal injury between 2013 and 2018. 

Results: Of the 15 cases, Kayexalate crystals were identified in 7 cases, Sevelamer in 5 cases and both together were seen in 3 cases. Resin crystals were identified in the gastric antrum&duodenum (3 cases), colon (9 cases in the left colon, 2 cases in the right colon) and anal canal (1 case). The histological tissue reactions included mucosal necrosis (1 case), inflammatory polyps (2 cases), mucosal ulcerations with granulation tissue formation (10 cases), perforation (1 case) , and luminal crystals (1 case).

Conclusion: Accurate and timely recognition of the resin crystals in biopsy samples with clinical correlation is mandatory to avoid serious complications.