A 27-year-old man with Addison's disease and diabetes mellitus presented with vomiting and abdominal pain. He was curled up on his left side, and could only groan when asked questions.
The patient was unable to give a history, but his girlfriend said he began vomiting after eating the night before and slowly became more confused during the night.
His blood pressure was 96/66 mm Hg, heart rate was 101 bpm, respiratory rate was 12 bpm, and temperature was 37.4°C.
A CT of the patient's abdomen is shown. What is the diagnosis?
Find a case discussion on page 19.
Intussusception occurs when one piece of intestine telescopes into another part of the intestine. It is more common in children than adults, and the cause is usually idiopathic without any identifiable lead point.
Intussusception is rare in adults, occurring only in one percent of intestinal obstruction cases. (Ann Surg. 1997;226:134; https://bit.ly/3JjF8Q7.) Intussusception in adults represents less than five percent of all intussusception cases. (BMC Gastroenterol. 2014;14:86; https://bit.ly/3JHmbIn.)
Intussusception often presents in children with the classic triad of abdominal pain, rectal bleeding, and a palpable abdominal mass. Most cases can be treated without surgical intervention. Unfortunately, adults with this condition often have nonspecific signs and symptoms, but the most common are abdominal pain, nausea, and vomiting. (Dis Colon Rectum. 2006;49:1546.) Adults can also present with obstructive symptoms. (Pediatr Emerg Care. 2012;28:842; http://bit.ly/3Jr9QqC.)
Cases of intussusception in adults are often caused from a pathological lead point, but they can also be caused by a benign lesion or just be idiopathic. One retrospective review found that 86 percent of adult intussusception cases were associated with a definable lesion, 29 percent of which were malignant. (Dis Colon Rectum. 2006;49:1546.) It also found that all ileocolic lesions were malignant and only 33 percent of the colonic lesions were malignant. The small bowel is more frequently affected by intussusception than the colon, although intussusception involving the colon is more likely to be malignant.
CT scanning is the best way to diagnose intussusception in adults. It will show a sausage-shaped mass that has a target sign. CT scans have a sensitivity of 58% to 100% and a specificity of 57% to 71% in identifying intussusception. (Int J Colorectal Dis. 2006;21:834.) The use of CT scans has made identifying asymptomatic and transient adult intussusception more frequent. The literature supports nonoperative management for patients without concerning symptoms for whom there is no lead point on CT scan. (Am J Surg. 2015;209:580; https://bit.ly/3LBKXv4.)
Ultrasound is first-line imaging for children. (World J Gastroenterol. 2012;18:5745; https://bit.ly/42oMQAW.) This study showed that ultrasound may be as high as 98% to 100% sensitive and 88% to 89% specific for diagnosing intussusception in children. (See image.) Ultrasound is unlikely to replace CT scans completely because of vague presentations in adults and the need to identify a lead point and surrounding factors, but it could be used as a first step to increase clinical suspicion if there is a wait for CT.
Intussusception has traditionally been significantly associated with a malignant lead point, and surgical exploration was often required. (Ann Surg. 1997;226:134; https://bit.ly/3JjF8Q7.) Significant advancements in CT technology and its more frequent use have led to transient intussusceptions being detected more frequently without underlying pathology. (Radiographics. 2006;26:733.) The literature supports a conservative approach in adults for intussusception seen on CT scan where the probability of malignancy is low, no lead point is identified, and no signs of ischemia are seen. (Int J Surg Case Rep. 2016;20:142; https://bit.ly/42pgXIA.)
Always involve your surgical colleagues in these patients' care. They will determine whether to use conservative or surgical management. Conservative and supportive management is appropriate if the patient's exam and CT hint at a more self-limiting process. This would include frequent abdominal rechecks, bowel rest, IV fluids, and laboratory tests and follow-up imaging as needed. Surgery is the likely next step if the case is equivocal, concerns a lead point with malignancy, or has concerning signs of obstructions.
Surgery was consulted immediately in this case, and they opted for conservative management with frequent abdominal rechecks, bowel rest, IV fluids, and repeat imaging.
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Dr. Kaplanis an assistant professor of emergency medicine at the University of Colorado School of Medicine in Aurora. Follow her on Twitter@bonniekaplan20, and read her past columns athttp://bit.ly/EMN-QuickConsult.