Colonoscopy Preparation-Related Ischemic Colitis Presenting as a Colonic Mass

Abstract

Purpose: The incidence of ischemic colitis is estimated to be 4.5 to 44 cases per 100,000 person-years. Patients typically present with painful diarrhea followed by hematochezia. This case report highlights an unusual presentation of ischemic colitis presenting with an obstructing mass mimicking colon cancer. A 66-year-old overweight female with 50 pack-years of tobacco use and chronic obstructive pulmonary disease presented as an outpatient with a change in bowel habit and hematochezia. The patient presented to the ER with diffuse severe abdominal pain and rectal bleeding following standard preparation for colonoscopy with polyethylene glycol solution. On examination her pulse was 118/min and tenderness was present in left lower quadrant without rebound tenderness, guarding, or rigidity. The WBC count was 14,000/uL, hemoglobin was 13.4 gm/dL, and MCV was 84.3. A CT scan showed proctosigmoiditis with segmental dilatation of the descending colon. A colonoscopy showed a 12-cm-long partially obstructing rectosigmoid mass starting 12 cm from anal verge. Above the mass erythema, edema, friability, ulceration, and surface hemorrhage were present. As a result it was difficult to delineate the proximal border of the mass. Multiple diverticula were seen in right colon. Biopsies of the mass showed small vessel vascular proliferation with hyaline thrombi suggestive of ischemic changes. In view of the endoscopic findings, which were highly suspicious for malignancy, a repeat colonoscopy was performed. Repeat biopsies showed hyalinized blood vessels with fibrinoid necrosis. The patient's symptoms did not improve with fluid resuscitation and antibiotics. Consequently, an exploratory laparotomy, left colon resection, proctectomy, and end colostomy with Hartmann's pouch were performed. At the time of surgery good pulses were noted in inferior mesenteric vessels. The final pathology confirmed ischemic colitis; there was no evidence of malignancy. A hypercoaguable workup was performed and was negative. Griffith's spot (splenic flexure) and Sudeck's point (junction of sigmoid colon and rectum) where collaterals converge are the areas most susceptible to ischemic injury. Ischemic injury can occur in other segments of the colon. Hyalinization of lamina propria, atrophic microcrypts, and transmural fibrosis are pathognomonic features of ischemic colitis. Edematous, hemorrhagic, or necrotic mucosa is seen in acute phase, while strictures or loss of haustrations can be found in the chronic phase. The finding of the mass is uncommon in patients with ischemic disease. This clinical vignette illustrates that patients with ischemic colitis may present with mass lesions in the chronic phase.