Case Presentation: A 94-year-old man with no significant past medical history presented to the Emergency Department with a two week history of progressively worsening constipation accompanied by nausea, vomiting, and abdominal pain. He denied any hematochezia, melena, change in stool caliber or unintentional weight loss. He had never undergone a colonoscopy. He had tried stool softeners as well as a home enema without relief of symptoms.
On presentation, vitals were notable only for hypertension at 162/100. Exam was notable for mild distension and mild tenderness to palpation in all quadrants. Abdominal radiograph demonstrated diffuse distension of the small and large bowel with a dilated cecum. CT imaging of his abdomen/pelvis demonstrated normal small bowel with a large amount of stool throughout the cecum, ascending colon and transverse colon without evidence of obstruction. He was admitted with working diagnosis of Ogilvie’s syndrome and treated with supportive cares, aggressive bowel regimen and avoidance of constipation-provoking medications. After supportive cares failed to relieve his symptoms, he underwent decompressive colonoscopy and was found to have near complete obstructing mass of the rectosigmoid colon. Pathology returned consistent with a moderately differentiated adenocarcinoma. Given his age and comorbidities, he underwent a diverting colostomy as a palliative measure and was ultimately discharged to home.
Discussion: In this case, abdominal CT results heavily swayed the initial differential towards Ogilvie’s syndrome. Abdominal CT has high sensitivity and specificity in detecting an obstructing colon cancer. In this case, a clear obstruction was not identified. Retrospectively, he did not have any provoking factors that are often associated with Ogilvie’s syndrome – such as surgical intervention, trauma, electrolyte abnormalities or opioid usage. He has had a higher pre-test probability of colon cancer given his age and no prior colonoscopy screening. This case was somewhat misleading as the patient continued to pass flatus and did not have worsening symptoms of nausea/vomiting suggestive of obstruction; though he did develop worsening abdominal distension prior to final diagnosis.
Conclusions: Abdominal CT with IV contrast has high sensitivity and specificity for identification of colon cancer, though should not be used to rule out a diagnosis of colon cancer when pre-test probability and clinical suspicion is high. In addition, the diagnosis of Ogilvie’s syndrome should be made after exclusion of mechanical obstruction.