Adult Intestinal Intussusception: Radiologic-Pathologic Correlation Poster No.: C-2355 Congress: ECR 2013 Type: Educational Exhibit Authors: C. Rubio Hervás, A. Verón Sánchez, A. Díez Tascón, D. Mollinedo, E. Canales Lachén, M. Marti; Madrid/ES Keywords: Obstruction / Occlusion, Metastases, Cancer, Surgery, Ultrasound, Fluoroscopy, CT, Gastrointestinal tract, Emergency, Abdomen DOI: 10.1594/ecr2013/C-2355 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 29
Learning objectives Describing the key imaging features associated with adult intestinal intussusception. Also discusses the CT findings that can help determining the appropriate treatment. Background Approximately 5% of all intussusceptions occur in adults, accounting for 1% of all bowel obstructions. Intussusception refers to the invagination of a bowel loop with or without mesenteric fat and mesenteric vessels (intussusceptum) into the lumen of a contiguous portion of the immediately more distal bowel (intussuscipiens). They are classified according to its location as: enteroenteric, ileocolic, ileocecal, or colocolic. In adults, it can be further classified on the basis of whether a lead point is present, which may pose a diagnostic challenge. Intussusception without a lead point tends to be an incidental finding, transient, that resolves spontaneusly, and do not require treatment. The majority of intussusceptions without a lead point occurs in the small bowel and usually appears as a nonobstructing segment, smaller in diameter and shorter than an intussusception with a lead point. A lead point intussusception involving the small bowel is generally due to a benign condition (lipoma, adenomatous polyp, Meckel diverticulum). More than one-half of large bowel intussusceptions are associated with malignant lesions. Symptoms related to an intestinal obstruction (prior history of episodic crampy abdominal pain, nausea, vomiting) or symptoms related to a neoplasia (constipation, weight loss, melena, palpable abdominal mass) suggests intussusception with a lead point. The degree of bowel wall edema due to impaired circulation of the mesenteric vessels may make a lead mass difficult to identify. CT appearances and identification of signs (cross-sectional bowel diameter, intraluminal mass, free fluid, altered perfusion) can provide a reliable radiologic indicator of an intussusception with a lead point. We have retrospectively reviewed sixteen cases of adult intestinal invagination from our database, identifying the signs leading to the diagnosis. Page 2 of 29
Images for this section: Fig. 1: Transient small bowel intussusception in a 27-year-old man with left lower quadrant pain. Contrast-enhanced CT scan demostrates an entero-enteric intussusception where we are able to identify a bowel loop which invaginates into the lumen of a contiguous portion of bowel. Page 3 of 29
Fig. 2: It is accompanied of mesenteric fat and blood vessels. Page 4 of 29
Fig. 4: Anteroposterior radiography from single-contrast barium enema shows delayed transit and increased intestinal secretion. No intussusception is observed. Page 5 of 29
Fig. 3: A delayed view of the same small bowel loop shows transient proximal jejunum intussusception, once passed duodeno-jejunal junction (angle of Treitz). Page 6 of 29
Fig. 5: Enteroenteric intussusception in a 98-year-old woman with abdominal pain and constipation. Contrast-enhanced CT scans of the abdomen shows a sausage-shaped mass enveloping a fat-containing structure. Page 7 of 29
Fig. 6: There is an abrupt change in caliber between the proximal dilated fluidfilled bowel loops and the collapsed distal ones. This change is due to enteroenteric intussusception. Poorly differentiated renal medullary carcinoma acted like lead point of the intussusception, although no tumor was identified in kidneys. An adjacent pathologic lymph node is also observed. Page 8 of 29
Imaging findings OR Procedure details SMALL BOWEL INTUSSUSCEPTION MECKEL DIVERTICULUM The most common congenital anomaly of the gastrointestinal tract (2-3% of the population). Complications: hemorrhage, small bowel obstruction and diverticulitis. It may invaginate or invert into the lumen serving as a lead point for an ileoileal or ilecolic intussusception. At CT: Central core of fat attenuation surrounded by a collar of soft-tissue attenuation LYMPHOMA Primary lymphoma of the gastrointestinal tract is a common entity (20-40% of all malignant tumors in the small bowel). Symptoms include: abdominal pain, weight loss, small bowel obstruction and acute abdomen. T-cell lymphomas are manifested as: Ulcerated plaques Fibrosis/strictures in the PROXIMAL small bowel B-cell lymphomas are manifested as: Annular or polypoid masses In the DISTAL and TERMINAL ILEUM At CT: Mesenteric or retroperitoneal lymphadenopathy Single or multiple masses, often with a large size, or nodular or diffuse parietal thickness affecting a large small bowel segment (more often terminal ileum) Hypodense small bowel wall (differential diagnosis with inflammatory/ infectious pathology cursing with bowel wall edema) Page 9 of 29
VENOUS MALFORMATIONS They may manifest with bleeding, anemia or, if they form a mass, with intussusception. The cecum is the most common site of venous malformations, followed by the right colon and the jejunum. Patients are normally elderly with a history of cardiovascular disease. In younger patients, look for atypical sites (small bowel). INFLAMMATORY FIBROID POLYP Also known as Vanek tumor (Vanek 1941). The stomach is the most common location, followed by the small bowel. It can ulcerate and cause gastrointestinal bleeding or be a cause of mechanical obstruction. Intussusception is rare. Malignancy is excepcional. MALIGNANT FIBROUS HISTIOCYTOMA It is the most common soft-tissue sarcoma late in life, occurring more frequently in the extremities, trunk and retroperitoneum. Rare in visceral organs. Unusual cause of small bowel intussusception. MALIGNANT NEOPLASM We have already said that a lead point intussusception involving the small bowel is generally due to a benign condition and less often to a neoplasm. When malignant neoplasm occurs, is usually a metastatic lesion, being the melanoma metastases the most common metastatic lesions of both small and large bowel (in order of frequency: small bowel > stomach > large bowel). LARGE BOWEL INTUSSUSCEPTION Identifying an underlying cause is not easy (except in lipoma). More than one-half of them are associated with malignant lesions: Adenocarcinoma > lymphoma > metastatic disease Ileocolic/ileocecal or colocolic. Transient tumor-related colocolic intussusception has been reported. Page 10 of 29
Ileocolic-Ileocecal The causes of ileocolic-ileocecal intussusception in adults are, in order of frequency, adenocarcinoma, lymphoma and metasstasic disease. Melanoma metastases are the most common metastatic lesions of both small and large bowel: Found in 2-5% of patients Small bowel > stomach > large bowel Intussusception is very rare Colocolic Lipoma The most common benign cause of colocolic intussusception The most common benign tumors of the colon Submucosal origin in 90% of cases Usually solitary DDx with mesentery and subserosal fat "Asymptomatic" Adenocarcinoma The most common malignant cause of colonic intussusception Symptomatic: bleeding, obstruction, palpable abdominal mass and abdominal pain Images for this section: Page 11 of 29
Fig. 7: Ileocecal intussusception in a 34-year-old man with right lower quadrant pain. There was a prior history of anemia. Contrast-enhanced CT shows ileocecal intussusception caused by an inverted Meckel diverticulum, which appears as a central core of fat surrounded by a collar of soft-tissue attenuation. Page 12 of 29
Fig. 8: The anatomopathological diagnosis demonstrates ectopic pancreas with adenomyomatosis in the inverted Meckel diverticulum head. Page 13 of 29
Fig. 9: Ileo-colic intussusception in a 29-year-old man with abdominal pain. Contrastenhanced CT scan demonstrates an amorphous mass due to a diffuse and homogeneus wall thickening of a large segment of bowel in the context of a large lymphoma of the ileum. The mass is isoattenuating relative to the bowel wall edema, making differentiation difficult. Page 14 of 29
Fig. 10: Duodeno-duodenal intussusception in a 56-year-old man with accute hypogastric pain. Contrast -enhanced CT scan of the abdomen shows the typical multilayered appearance of small bowel intussusceptions. Page 15 of 29
Fig. 11: There is a groove pancreatitis which may mimic a pancreatic head carcinoma. The inflammation changes are located at the groove between the head of the pancreas, the duodenum and the common bile duct. Page 16 of 29
Fig. 12: Upper cross-sectional image shows intra and extrehepatic biliary dilatation (right) and chronic pancreatitis changes including atrophy of the organ, main pancreatic duct dilatation and calcification (left). Page 17 of 29
Fig. 13: Ileoileal intussusception in a 75-year-old woman with metastatic melanoma presenting accute left lower quadrant pain. Contrast material-enhanced CT scan of the abdomen shows the typical multilayered appearance of small bowel intussusception. The intussusceptum, with an accompanying complex of mesenteric fat and blood vessels, is surrounded by thick-walled intussuscipiens. Note metastase actuating like lead mass originating in the distal ileum. Page 18 of 29
Fig. 14: Multiple large pedunculated polypoid masses in stomach and small bowel, and rounded masses in mesenteric fat, retroperitoneum and celullar subcutaneus tissues are also observed. Page 19 of 29
Fig. 15: Note the presence of a heterogeneous mass in left lung. Fig. 16: Ileo-colic intussusception secondary to adenocarcinoma in a 98-year-old woman. Contrast-enhanced CT scans of the abdomen show the classic finding of a sausageshaped mass. Mesenteric fat and blood vessels are well visible accompanying the intussusceptum loop. Page 20 of 29
Fig. 17: Photograph of the gross surgical specimen shows the ileocolic intussusception. Page 21 of 29
Fig. 18: Photograph of the gross surgical specimen shows the ileocolic intussusception. Page 22 of 29
Fig. 19: Axial US scan in a 87-year-old woman with right lower quadrant pain. US scan obtained near the apex shows multiple concentric rings (a hypoechoic surrounding a hyperechoic one, which surrounds another hypoechoic ring). Hypoechoic outer ring is formed by the everted limb of the intussusceptum and the intussuscipiens and the center varies with the section level. Page 23 of 29
Fig. 20: US scan obtained at the base of the intussusception shows the central limb of the intussusceptum eccentrically surrounded by the hyperechoic mesentery, a situation that produces the doughnut sign. An additional hypoechoic area which represents a lymph node is also observed. Page 24 of 29
Fig. 21: Doppler US scan show blood flow within the intussusceptum and mesentery. Page 25 of 29
Fig. 22: Ileocolic intussusception secondary to adenocarcinoma in the previous patient. Contrast-enhanced CT scans of the abdomen show the classic findings of a lead point intussusception with invaginated mesenteric fat and vessels. The tumor serving as the lead point originates at the cecum. Note the lymphadenophaty measured in Fig. 20. Page 26 of 29
Fig. 23: Ileocolic intussusception secondary to adenoacarcinoma in a 79-year-old man. Page 27 of 29
Fig. 24: Photograph of the gross specimen shows the invagination of the ileum into the adjacent large bowel. Page 28 of 29
Conclusion The widespread application of CT in different clinical situations has increased the level of detection of intussusceptions Abdominal CT plays an important role in distinguishing between lead point intussusception and non-lead point intussusception and has the potential of reducing the prevalence of unnecessary surgery Radiologists should be familiar with CT appearances and be well trained in the identification of a causative lead point References 1. 2. 3. 4. 5. 6. 7. 8. Azar T, Berger DL. Adult intussusception. Ann Surg 1997; 226: 134-138. Agha FP. Intussusception in adults. AJR 1986; 146: 527-531. Kim YH, Blake MA, Harisinghani MG, et al. Adult intestinal intussusception: CT appearances and identification of a causative lead point. Radiographics 2006; 26: 733-744. Jain P, Heap SW. Intussusception of the small bowel discovered incidentally by computed tomography. Australas Radiol 2006; 50: 171-174. Knowles MC, Fishman EK, Kuhlman JE, Bayless TM. Transient intussusception in Crohn's disease: CT evaluation. Radiology 1989; 170: 814. Lvoff N, Breiman RS, Coakley FV, Lu Y, Warren RS. Distinghuishing features of self-limiting adult small-bowel intussusception identified at CT. Radiology 2003; 227: 68-72. Levy AD, Hobbs CM. From the archives of the AFIP: Meckel diverticulum - radiologic features with pathologic correlation. RadioGraphics 2004; 24: 565-587. Kanoh T, Shirai Y, Wakai T, Hatakeyama K. Malignant fibrous histiocytoma metastases to the small intestine and colon presenting an intussusception. Am J Gastroenterol 1998; 93: 2594-2595. Personal Information Page 29 of 29