So easy (to dignose) but so dificcult (to find in adults)

Clinical History

A 57 year old white female after 2 weeks was readmitted to hospital with abdominal pain worsening and incoercible vomiting with diminution of bowel sounds. Abdominal CT showed bowel-within-bowel with no regional enlarged lymph nodes. The patient underwent partial enterectomy confirming intussusception caused by 2.3 cm tumour.

Imaging Findings

This case is about a 57 year old white female, with irrelevant personal or familial background, that went to hospital in February (2009) because she had epigastric pain with dorsal irradiation with no aggravation or relief factors and vomiting denying weight lost. She was discharged with a diagnosis of gastroenteritis. After 2 weeks she was admitted to hospital for abdominal pain worsening and incoercible vomiting. Her physical examination revealed pain on superficial and deep palpation especially in the upper left abdomen, with diminution of abdominal sounds. In laboratory analysis there was only leukocytosis with neutrophilia. Physicians suspected of proximal gastrointestinal occlusion because of the incoercible vomiting and an abdominal CT scan was performed showing pathognomonic bowel-within-bowel with contained fat and mesenteric vessels (Fig 1), compatible with jejunojejunal intussusception, with reduced enhancement of the distal segment of the small bowel wall involved in the intussusception, probably in relation with some ischemic oedema (Fig 2). There were no detectable regional or mesenteric enlarged lymph nodes. The patient underwent partial enterectomy conditioned by tumour with about 2.3 cm (Fig 3b,c) and there was also segmental wall ischemia (Fig 3d). The pathologic exam revealed B-cell (CD-20) follicular lymphoma.

Discussion

Intussusception is the invagination of proximal intestinal bowel loop and its mesenteric fold (intussusceptum) into the lumen of contiguous portion of distal bowel loop (intussuscipiens) as a result of peristalsis. It can be classified according to location (enteroenteric, ileocolic, ileo-cecal or colocolic), cause (benign, malignant or idiopathic) and whether a lead point is present. Intussusception is one of the most common causes of bowel obstruction in infants and toddlers and is most often (80%) ileocolic. Most children (95%) do not have an identifiable specific lead point. In these idiopathic cases, careful examination may reveal hypertrophied mural lymphoid tissues (Peyer patches), which are usually due to viral infection. A specific lead point is identified in only 5% of cases. In infants aged 6 months to 2 years, intussusception is not unusual and often follows an upper respiratory tract infection or gastroenteritis and apparently is associated with seasonal peaks (spring, summer and winter).
Intussusception in adults is rare, accounting for approximately only 5% of all intussusceptions, causing only 1% of all bowel obstructions. About 90% of cases have a demonstrable cause such as neoplasia (approximately 65% of the cases) or postoperative condition. Malignant tumours are more common (about 70% of the cases) than benign tumours in colon, although the reverse is true to the small bowel. It is believed that masses in the intestine act as "irritant" and provoke abnormal peristaltic movement which may lead to the telescoping movement of one bowel segment over the adjacent. Often in intussusception with a lead point, there is a prior history (weeks-months) of episodic abdominal pain, nausea and vomiting, symptoms that suggest partial intestinal obstruction and rarely manifests with acute abdomen. It may also manifest with symptoms related to a neoplastic process such as palpable mass, melena, weight loss or constipation, more frequent in large bowel intussusception. Intussusception is well diagnosed in CT, which shows a pathognomonic bowel-inside-bowel with or without fat and mesenteric vessels, and appears as a "sausage-shaped" mass or as "target like" according to CT beam is parallel or perpendicular to its longitudinal axis, respectively. The presence of a lead point, morphology of the leading mass, the degree of mural edema and the amount of invaginated mesenteric fat, affect the appearance of an intussusception making the identification of the intussusception lead point difficult. CT findings of regional or mesenteric lymphadenopathy associated with a bowel wall mass can help distinguish lymphoma from other bowel diseases, but when CT demonstrates mild bowel wall thickening with small lymph nodes, the detection of the underlying cause of intussusception may be difficult because differentiation from bowel wall oedema may be not possible.
Primary lymphoma of the gastrointestinal tract accounts for approximately 20-40% of all malignant tumours in small bowel. Usually they present with abdominal pain, weight loss, small bowel obstruction and sometimes acute abdomen. T-cell lymphomas typically manifest as ulcerated plaques or strictures in the proximal small bowel, whereas B-cell lymphomas tend to manifest as annular or polypoid masses in the ileum.

Differential Diagnosis List

Final Diagnosis

Enteroenteric intussusception caused by primary small bowell B-cell lymphoma

URL:	https://www.eurorad.org/case/7775
DOI:	10.1594/EURORAD/CASE.7775
ISSN:	1563-4086