Simultaneous CMV Colitis and Kayexalate-Induced Ulcer Presenting as Hematochezia

Abstract

We present a rare case of hematochezia caused by 2 concurrent ulcers caused by different etiologies: CMV and Kayexalate (sodium polystyrene). A 66 year old man with history of deafness and HCV cirrhosis with prolonged hospitalization from a motor-vehicle accident had multiple episodes of hematochezia with a resultant decrease in hemoglobin from 8.2mg/dL to 5.3mg/dL. Colonoscopy was performed, which showed two relatively isolated ulcers located in the transverse colon and in the rectum. The remainder of the colonic mucosa, however, was normal. Both ulcers were biopsied for pathology. Surprisingly, the rectal ulcer demonstrated findings of crystal-like structures suggestive of Kayexalate crystals, while the transverse ulcer stained positive for CMV on viral immunohistochemistry stains. Upon review of the patient's chart, he received 2 separate doses of Kayexalate 5 days prior and immediately prior to endoscopy for transient hyperkalemia due to acute renal failure. He did not have diarrhea or increased number of bowel movements prior to colonoscopy. There was no obvious evidence of immunodeficiency or compromise. He was started on gancyclovir for his CMV colitis and Kayxelate was no longer used during his hospitalization. The patient subsequently did well with no further hematochezia. There are a number of cases that describe ulcers caused by Kayexalate, however, simultaneous infection with CMV has not been reported. Rare causes of hematochezia can be missed if the entire colon is not examined. Obtaining a biopsy of each ulcer should be considered because management can change depending on pathology results. Careful review of medications and associated medical conditions can help broaden the suspected differential diagnosis during cases.Figure: Transverse colon ulcer.Figure: Kayexalate crystal from rectal ulcer biopsy.