Abstract
Intussusception is defined as the invagination of a proximal segment of the bowel into the adjoining or distal segment. In most adults with intussusception, there is a demonstrable lead point with a definite pathologic abnormality. The clinical features of intussusception include chronic intermittent abdominal pain, nausea and vomiting, constipation, and a palpable abdominal mass. The present case report describes a 62-year-old woman with a 2-week history of abdominal pain and 9-day history of vomiting. Clinical, imaging, and histologic evaluations revealed a jejunojejunal intussusception with a gastrointestinal stromal tumor as the lead point. A gastrointestinal stromal tumor should be considered as a possible lead point in adult patients with intussusception. The implication of reducing the intussusception prior to tumor resection requires further evaluation in view of the risk of venous embolism, including direct spread of malignant cells, in cases involving a large polypoid mass with a necrotic surface that extends to the serosa as shown by intraoperative examination. Accordingly, the rationale for adjuvant therapy with imatinib also requires further evaluation.
Keywords
Introduction
Intussusception is defined as the invagination or telescoping of a proximal segment of bowel into the adjoining or distal segment.1,2 It is an uncommon cause of intestinal obstruction in adults. Among adult patients, intussusception accounts for 5% of all cases of intussusception and 1% of intestinal obstructions.3–5 In 70% to 90% of intussusceptions in adults, there is a demonstrable lead point with a definite pathologic abnormality, and 65% of lead points involve a neoplastic abnormality.4,6 Intussusception may present with acute, subacute, or chronic nonspecific symptoms. 4 Depending on the location of the etiology, the clinical features of intussusception may include chronic intermittent abdominal pain, nausea and vomiting, constipation (features of bowel obstruction), or a palpable abdominal mass.1,7 Diagnosis can be difficult in adults because of the nonspecific symptoms. 8 Abdominal computed tomography (CT) is the most sensitive imaging technique for the diagnosis of adult intussusception, with the target sign being the main diagnostic feature. 8 Surgical intervention is ideal; however, no consensus has been reached regarding reduction of the intussusception prior to resection when a malignant pathology is suspected to be the lead point. 8 The prognosis depends on the pathology of the lead point; the prognosis is worse for malignant lesions and depends on the adequacy of resection, tumor size, mitotic activity, and site. 4 We herein present a case involving a 62-year-old woman with a 2-week history of abdominal pain and 9-day history of vomiting. Clinical, imaging, and histologic evaluations revealed a jejunojejunal intussusception with a gastrointestinal stromal tumor (GIST) as the lead point. This case highlights the risk of malignant spread during reduction of the intussusception prior to tumor resection. We also herein discuss the possibility of dissemination of malignant cells during the development of an intussusception (sometimes recurrent) involving a tumor known for its risk of hematogenous spread and the possible need to consider adjuvant therapy with imatinib.
Case report
A 62-year-old woman presented with a 2-week history of abdominal pain and 9-day history of vomiting. She had been clinically well until 2 weeks prior to presentation, when she developed abdominal pain. The pain was characterized by gradual onset, was located in the right upper abdomen and later became generalized, and was initially colicky but then progressively worsened. The patient began vomiting approximately 5 days after the onset of abdominal pain. She vomited up to twice daily, and the vomiting was mostly postprandial and projectile. It was of moderate volume, contained recently ingested food, and was bilious but non-bloody. She also had an associated history of nausea, loss of appetite, weight loss, and abdominal distention. The patient was taking medications for asthma.
Upon presentation, the patient was in distress due to pain. Physical examination revealed that she was afebrile, was neither pale nor icteric, and was moderately dehydrated. She had no pedal edema and no peripheral lymph node enlargement. Her vital signs were normal. Her abdomen was mildly distended and moved with respiration; it was soft with tenderness in the right upper quadrant, and a soft sausage-shaped mass extending from the epigastrium to the right iliac fossa was palpated. Digital rectal examination was unremarkable. The patient was clinically diagnosed with intestinal obstruction secondary to intussusception. Laboratory investigations revealed a packed cell volume of 32% and normal serum electrolyte levels and urinalysis findings. Plain abdominal X-ray examination findings were suggestive of an intestinal obstruction, and ultrasound examination revealed an ileoileal intussusception.
The patient underwent an emergency exploratory laparotomy, which revealed a jejunojejunal intussusception of approximately 16 cm with a viable intussusceptum and intusscucipiens (Figure 1). The intussusception was reduced (Figure 2). An approximately 12-cm segment of bowel with the tumor in situ was resected, and end-to-end anastomosis was performed. The bisected resected segment showed a 4-cm nodular, variegated polyp with a sessile base, with the tumor extending to the serosa at the antimesenteric border. The adjoining mucosal surface showed the typical valvulae conniventes of the jejunum (Figure 3). The patient’s immediate postoperative condition was satisfactory, and her postoperative recovery was uneventful. The patient was discharged on day 12 following surgery. Macroscopic examination showed a fungated polypoid mass with necrotic surfaces (Figure 3). The mass was polypoid and extended from the serosal surface at the antimesenteric border (3 cm at the widest dimension). Microscopic examination confirmed intestinal tissue with a mesenchymal tumor composed of spindle-shaped and epithelioid cells infiltrating into the stroma (mixed-type GIST) (Figure 4(a, b)). The residual intestinal margins were reported as tumor-free and viable. The definitive diagnosis was jejunojejunal intussusception with a pathological lead point caused by a GIST. The patient was lost to follow-up in the surgical outpatient department 2 months postoperatively.
Clinical photograph of jejunojejunal intussusception.
Photograph of jejunum with finger pointing at the pathological lead point post-reduction.
Resected intestinal segment showing the jejunal mucosa (blue arrow) and a polypoid multilobulated tumor (red arrow).
Hematoxylin and eosin staining revealed a mesenchymal tumor composed of spindle-shaped and epithelioid cells infiltrating the stroma. (a) 40× and (b) 100×.
The patient provided both verbal and written informed consent for the reporting of this case and all accompanying images. The requirement for ethics approval was waived because this study was a report of a case managed by a clinical team at the University of Calabar Teaching Hospital and not an interventional study (i.e., no intervention or experimentation was conducted for the purpose of the study). The reporting of this study conforms to the CARE guidelines. 9
Discussion
Intussusception is the telescoping or invagination of a proximal part of the intestine (intussusceptum) into a distal or nearby portion (intussuscipiens), resulting in an obstruction of the bowel.1,6,8,10 Intussusception is clinically rare in adults. 4 Malignant disease of the small bowel is equally rare, affecting 0.7 to 1.6 in 1,000,000 individuals. 6 This occurs despite the high epithelial cell turnover in this segment of the intestine, constituting 90% of the mucosal surface area and 75% of the length of the entire intestine. 11 In the United States, small bowel malignancy accounts for only 2% of all gastrointestinal neoplasms and <0.4% of all cancers. 6 The mean age at presentation is reportedly 44.5 years, with a male:female ratio of 1.1:1.0. 3 The incidence of carcinoma and carcinoids is twice as high in Blacks as in Whites. 12 The risk of malignancy is expected to increase with age. Approximately 30% of GISTs are found in the small bowel, where they tend to be more aggressive than at other locations. 12
Intussusception has been classified as follows based on its location in the gastrointestinal tract: enteroenteric (jejunojejunal (Figure 1) and ileoileal), colocolic (involving the large bowel), ileocolic (terminal ileum into ascending colon), ileocecal (terminal ileum into ascending colon), and ileocecal (ileocecal valve acts as the lead point).2,7 Six separate regions of intussusception within the small bowel have been described, and these have become especially clear with the increasing use of CT. 13 In 70% to 90% of cases of intussusception in adults, a pathologic condition functions as the lead point4–6 (Figure 3). The lead points of small bowel intussusception in adults are benign lesions in 60% of cases, malignant lesions in 30%, and idiopathic in 10%.6,8,10 Tumors that function as lead points of invagination appear to have some common characteristics: they are usually bulky, polypoid, and relatively mobile. In addition, they have a submucosal or intraluminal pattern of growth usually arising from the antimesenteric border (Figure 3), and when malignant, they are not accompanied by a significant desmoplastic reaction. 6 The mechanisms involved in intussusception are not fully understood. The condition is believed to result from a lesion in the bowel (lead point) that alters the peristaltic pattern of the bowel, resulting in invagination. When no lead point is present, the intussusception may be due to submucosal bowel edema, fibrous adhesions, or dysrhythmic contractions.4,13 In adults, intussusception may also be due to intestinal malformation. 14
Adult patients with intussusception present with chronic and nonspecific symptoms of intestinal obstruction. Abdominal pain is the most common symptom, followed by nausea and vomiting and a palpable abdominal mass.4,8,10 Wang et al. 15 classified the clinical presentation into three categories based on the symptom duration: acute symptoms (<4 days), subacute symptoms (4–14 days), and chronic symptoms (>14 days).
The use of preoperative imaging may help to identify the causative lesion. The first diagnostic tool is plain abdominal X-ray examination, which may demonstrate features of intestinal obstruction. Upper gastrointestinal barium studies show a stacked coin or coiled spring sign, and a barium enema shows a cup-shaped filling defect. 4 Ultrasound examination may demonstrate a target/doughnut sign or pseudo-kidney sign. 4 CT has diagnostic accuracy of 58% to 100% when the characteristic target sign is shown, and it is reportedly the most useful diagnostic tool for intestinal intussusception.4,5,7 CT may be used to characterize the mass as smooth, irregular, or lobulated. 12 The absence of CT was a significant deficiency in the work-up of our patient.
Mesenchymal tumors constitute 1% of primary gastrointestinal cancers, with GISTs being the most common. The annual incidence of GISTs ranges from 7 to 20 cases per million individuals. GISTs occur mainly in middle-aged and older individuals and are reportedly rare in people aged <40 years. 4 They originate from the interstitial cells of Cajal and may be found anywhere throughout the gastrointestinal tract from the esophagus to the anus. However, they are most commonly found in the stomach (40%–60%), small bowel (25%–30%), colorectum (5%–15%), and esophagus (<1%). 4
Surgery is the treatment of choice for adults with intussusception in view of the association with a pathological lead point, which was revealed to be a GIST in the present case. Surgery is the standard of care for localized GISTs and may be accomplished by laparoscopy or laparotomy.5,12 Intraoperative histopathological evaluation of frozen sections should be part of the preoperative plan in adult patients with intussusception because it may inform the need for a change in the operation plan. Controversy exists regarding the management of adult intussusception of the small bowel by reduction prior to tumor resection considering the risk of venous embolization, including seeding of malignant cells, in addition to a short bowel segment without reduction.4,7,8 This risk was highlighted in the surgical and histological findings of our patient, who had a polypoid mass with a necrotic surface that extended from the serosal surface at the antimesenteric border (3 cm at the widest dimension) to the mucosa (Figure 3). Whether such patients can benefit from adjuvant therapy with imatinib requires further research.
Postoperative histology is required to determine the adequacy of the surgery. Histologic examination in our patient confirmed a GIST with tumor-free resection margins. 3 However, whether further management is required for large GISTs remains unresolved (Figure 3). The risk of venous embolism by manipulation of the tumor during reduction of the intussusception must also be considered. Further pathological assessment includes immunohistochemistry for CD117, CD34, and DOG1 as well as mutational analysis, which can have prognostic and predictive value for some patients. 11 Adjuvant imatinib can delay recurrence and metastasis. 12 However, the rationale for a combination of surgery plus pathologic and pharmacologic intervention in our patient remains unclear, and risk evaluation of such patients is an area for further study. A 5-year survival rate of approximately 25% has been reported for patients with malignant small bowel GIST. 12
In conclusion, a GIST should be considered as a possible lead point in adult patients with intussusception. The definitive diagnosis is attained by postoperative histology. The implication of reducing the intussusception prior to tumor resection requires further evaluation in view of the risk of venous embolism, especially with large tumors. The rationale for adjuvant therapy with imatinib also requires evaluation.
