Intussusception in the Adult Patient: Rare, Ominous

A 33-year-old old man with no chronic health concerns, other than well controlled hypertension and an impaired fasting blood sugar, presented to his primary care provider complaining of a possible kidney infection. The patient reported having pain in his left lower back that radiated to the left upper quadrant. Other reported symptoms included increased urinary frequency and dysuria. He denied any fever, discharge, nausea, vomiting, or present encounters with multiple sex partners.

[[{"type":"media","view_mode":"media_crop","fid":"44798","attributes":{"alt":"","class":"media-image media-image-right","height":"415","id":"media_crop_6244912868426","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"5045","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"float: right;","title":"Figure. \"Target sign\" ","typeof":"foaf:Image","width":"462"}}]]Temperature at visit was 97.7° F. Urine analysis was negative for RBCs, WBCs, nitrites, or other findings. Physical exam revealed left sided CVA tenderness, LUQ tenderness and tenderness on the left flank. Point of care CBC was ordered and revealed a normal white count without left shift. A stat CT of the abdomen and pelvis with contrast was ordered; all visualized organs were unremarkable except for the small bowel which revealed a likely intussusception of the jejunem in the patient’s left midabdomen (Figure). The patient was instructed to report to the emergency department (ED) for evaluation. Repeat UA and blood chemistries were unremarkable. Office findings were reproduced on ED evaluation. Surgical consult was requested based on CT finding. After consult with general surgery, and symptomatic improvement in the ED, the patient was discharged home with a clear liquid diet, pain medication and instructions to follow-up with general surgery in one week. At that time, no new complaints were made, and no masses or tenderness to palpation on exam was elicited. He was then instructed to follow up as needed.

Discussion

Intussusception is the most common cause of bowel obstruction in children, and it is a rare cause in the adult patient, accounting for only 1-5% of bowel obstructions.¹

While the cause of the intussusception is rarely found in the pediatric patient, most cases in adults have an identifiable cause with over half being a result of malignancy. Causes of intussusception are much more rare in the adult patient, but the differential would include inflammatory bowel disease, adhesions, and polyps.²

In the adult patient, the most common presentation of intussusception is chronic intermittent cramping abdominal pain associated with nonspecific signs of bowel obstruction including nausea, vomiting, fever, diarrhea, constipation, and rectal bleeding.³

Usually, as with this patient, the diagnosis of intussusception is made via abdominal CT and the finding of the “target sign”-a soft-tissue mass consisting of an outer intussuscipiens and central intus­susceptum-is essentially pathognomonic. Other imaging studies, while less sensitive or specific, can be utilized to confirm the diagnosis such as plain films of the abdomen, upper GI series, and barium enema.³

The etiology of intussusception in the adult patient is most often a malignant lesion thus surgery with resection is typically the treatment of choice.³  It is important to note that the incidental finding on CT of nonobstructing intussusception in a patient without other symptoms does not require intervention.³

While it is a rare finding, intussusception should always be included in the differential for small bowel obstruction in the adult patient because of its potential as the presenting sign of malignancy.

References:

• Aref H, Nawawi A, Altaf A, Aljiffry M. Transient small bowel intussusception in an adult: case report with intraoperative video and literature review.BMC Surgery. 2015;15:36. doi:10.1186/s12893-015-0020-6
• El-Sergany A, Darwish, A, Mehta P, Mahmoud, A. Community teaching hospital surgical experience with adult intussusception: Study of nine cases and literature review.Int  J Surg Case Rep. 2015;12:26–30. doi:10.1016/j.ijscr.2015.03.032
• Lu T, Chng Y. Adult intussusception.Perm J. 2015;19:79–81. doi:10.7812/TPP/14-125 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4315384/