British Journal of Radiology (2005) 78, 30-33
© 2005 British Institute of Radiology
doi: 10.1259/bjr/68274086
Enlarged mesenteric lymph nodes in asymptomatic children: the value of the finding in various imaging modalities
V Rathaus, MD1,
M Shapiro, MD1,
M Grunebaum, MD2 and
R Zissin, MD1
1 Department of Diagnostic Imaging, Sapir Medical Center affiliated to Sackler Medical School, Tel-Aviv University, Tel-Aviv and 2 Veteran Paediatric Radiologist, Kfar Saba, Israel
 |
Abstract
|
|---|
The purpose of this study was to determine the prevalence of enlarged mesenteric lymph nodes in asymptomatic children. We prospectively studied 189 consecutive asymptomatic children from the outpatients' nephrological clinics who were referred for abdominal ultrasound. For comparison, we retrospectively reviewed the abdominal CT studies of 99 children, performed following blunt abdominal trauma. The children of both groups were divided into four subgroups according to their ages. The size, the number and the morphology of mesenteric lymph nodes were assessed. On abdominal ultrasound, enlarged mesenteric lymph nodes were detected in 55 of 189 asymptomatic children (29.1%). The longitudinal diameter of the lymph nodes ranged between 5 mm and 19 mm. These lymph nodes were arranged in clusters (three to nine in number in a cluster). All the lymph nodes were oval-shaped, flattened, and without any discomfort following graded transducer compression. On abdominal CT, enlarged mesenteric lymph nodes were diagnosed in 28 of the 99 children (28.3%). These lymph nodes measured more than 5 mm and were arranged in clusters (three or more in number). In seven of these children associated minimal mural thickening of the terminal ileum was seen. The presence of enlarged mesenteric lymph nodes in asymptomatic children of all ages and in both sexes is a common, non-specific finding and should be evaluated only in the appropriated clinical context.
|
Introduction
|
|---|
The ultrasound identification of mesenteric lymph nodes (MLNs) in children with acute abdominal trauma is considered an incidental, non-specific finding, especially when the examination is performed with graded compression [1]. Enlarged MLNs are often seen in children with mesenteric lymphadenitis, but may also be found in asymptomatic children [1–4]. The prevalence of such enlarged lymph nodes in asymptomatic children has rarely been assessed [1–3].
We have examined prospectively the prevalence of enlarged MLNs in asymptomatic children, who underwent an abdominal ultrasound examination for follow-up of renal pathologies and we wish to report our experience with these cases. In addition, we reviewed retrospectively the prevalence of enlarged MLNs in children who had abdominal CT examination for abdominal trauma and were otherwise symptom free. The results of these two groups have been compared.
|
Material and methods
|
|---|
We evaluated two separate groups of children.
Group 1
This group was a prospective cohort of 189 consecutive children from the outpatient nephrological clinics (126 boys and 63 girls), whose ages ranged from 1 month to 16 years (mean age 4.8 years). The children were referred for an elective abdominal ultrasound between 1 January, 2003 and 30 June, 2003 for a variety of urological or developmental conditions. All were asymptomatic at the time of the examination, and had negative urine culture. Indications for the ultrasound examination are summarized in Table 1
.
All studies were performed by a paediatric radiologist (VR) with a 7–12 MHz linear transducer HDI 5000 SonoCT ATL (Philips, Israel). Oblique, transverse, and longitudinal scans of the lower abdomen were obtained by means of the graded ultrasound compression technique, described by Puylaert [5]. No fasting was required for the examinations.
Group 2
This group consisted of a cohort of 99 children who underwent an abdominal and pelvic CT after sustaining blunt abdominal trauma between the years 1998 and 2002. This group of otherwise healthy children prior to the examination included 77 boys and 22 girls with an age ranging between 1 year and 18 years (mean age 9.7 years). Table 2 summarizes the site of the abdominal injuries diagnosed by CT.
The CT studies were performed with one of two scanners: a conventional non-helical (Elscint 2400 Elite; Philips) with a slice collimation ranging from 5 mm to 10 mm and at 5–10 mm interval (depending on the age and the size of the child); or by a helical CT (Picker Mx Twin-flash) using a slice collimation of either 5.5 mm or 8 mm with a reconstruction interval of 5–6 mm, from the diaphragm down to the symphysis pubis. All patients received diluted water-soluble contrast material orally. Intravenous, non-ionic contrast of Ultravist (Iopromide, Schering, Germany) (2–3 ml kg–1) was injected by bolus. All CT examinations were reviewed retrospectively by two radiologists (VR and RZ).
The children of both groups were divided into four subgroups according to their ages and gender at the time of the study: 0–1 years, 2–6 years, 7–10 years, 11–15 years.
The definition of enlarged MLNs was based on the following criteria:
1. On ultrasound: a lymph node with a longitudinal diameter of more than 4 mm and in a cluster of at least 3 nodes [1];
2. On CT: a node measuring 5 mm or more, and appearing in a cluster of three or more glands located in the small bowel mesentery or in the right lower quadrant (RLQ) [6].
Statistical analysis
We analysed the differences of the prevalence of enlarged MLNs between the two groups, and in the different age subgroups using the chi squared test on SPSS for Windows (SPSS Inc., Chicago, IL).
|
Results
|
|---|
Group 1
Enlarged MLNs were detected in 55 of the 189 asymptomatic children (29.1%), 33 males and 22 females. The longitudinal diameter of the lymph nodes ranged between 5 mm and 19 mm and the number of the enlarged nodes seen in a cluster varied between three and nine (Figure 1). Tables 3 and 4 summarize the number and size of the MLNs detected by ultrasound per age subgroup. All the lymph nodes were oval-shaped and flattened following graded compression. No discomfort was elicited during the transducer compression. The enlarged nodes were mainly located in the RLQ, lateral and/or anterior to the right common iliac vessels or at the level of the inferior vena cava bifurcation. The presence of enlarged MLNs was significantly higher in children aged between 2 years and 10 years (p=0.006). No significant gender difference was noted in the presence, number or size of the detected nodes.
View larger version (107K):
[in this window]
[in a new window]
|
Figure 1. A 9-year-old child referred for an abdominal ultrasound for a single kidney follow-up. An abdominal ultrasound at the right lower quadrant: transverse view shows a cluster of four enlarged lymph nodes (arrows).
|
|
Group 2
Enlarged MLNs were diagnosed in 28 of the 99 children (28.3%) who underwent abdominal CT (Figure 2). 20 were males and 8 females. Table 5 summarizes the number of MLNs per age group detected by CT. In seven children a minimal mural thickening (<5 mm) of the terminal ileum was also seen. In all patients the appendix was normal. In 6 of 99 children no traumatic findings were detected on the CT. In 3 of 6 cases, MLNs were enlarged, and in one of them minimal mural thickening of the terminal ileum was also seen. 14 patients suffered from injury of the intestine and omentum, in five of them enlargement of the MLNs was detected, and in two cases, associated with minimal thickening of the terminal ileum.
View larger version (124K):
[in this window]
[in a new window]
|
Figure 2. An 8-year-old boy after motor vehicle accident. Contrast-enhanced CT at level of the upper pelvis shows a cluster of lymph nodes (arrows) are seen in right lower quadrant mesentery.
|
|
|
Discussion
|
|---|
Nowadays, the improvement of the ultrasound equipment has increased the detection rate of MLNs and mesenteric lymphadenopathy is a common ultrasound finding in children with acute, chronic and/or recurrent abdominal pain [1, 2, 4]. Enlargement of MLNs is often related to primary mesenteric adenitis, frequently caused by viral infection, Yersinia enterocolitica or Yersinia pseudotuberculosis infections [5]. Primary mesenteric adenitis is believed to occur more frequently in children than in adults [6]. This is a clinical entity related to a benign inflammation of the lymph nodes in the bowel mesentery, usually within the RLQ, without an identifiable acute inflammatory process or with mild (<5 mm) mural thickening of the terminal ileum [6, 7]. In these patients the clinical presentation is non-specific including abdominal pain, fever and leukocytosis mimicking a broad spectrum of different clinical diagnoses, such as acute appendicitis, infectious enterocolitis and pyelonephritis [1, 8].
Mesenteric lymphadenopathy may also be secondary to a detectable or known intra-abdominal inflammatory process such as acute appendicitis, Crohns' disease or systemic lupus erythematosis [6].
Enlargement of MLNs, however, may also be detected in asymptomatic children [1–4]. In our series we have found such enlarged nodes in 28.3–29.1% of asymptomatic children examined by CT or ultrasound, respectively, who had neither antecedent abdominal complaints nor tenderness during graded compression on ultrasound. This finding had the greatest prevalence in the age group between 2 years and 10 years old without a gender predilection. These lymph nodes were all smaller than 20 mm, elliptical in shape, and demonstrated no tenderness during compression. When these characteristics were present, it is more feasible to assume that these nodes represent a non-pathological finding [2]. The most common location is around the iliac vessels. Since this region also involves lymphatic drainage from the lower limb, the significance of enlarged lymph nodes in this area may not only be related to abdominal pathology. Watanabe et al [2] also detected enlarged ileocecal lymph nodes in asymptomatic children examined by ultrasound, with a slightly lower incidence (26 of the 122 cases; 21%). In addition, they found that the shape and the size of the detected lymph nodes, as well as their tenderness, during compression, could be used as an imaging criterion for distinguishing normal from pathological lymphadenopathy [2]. Healy and Graham [3] also reported that the size of the lymph nodes and their number appeared to play an important role in differentiating normal from pathological MLNs. Different results were reported by Sivit et al [1], using the same measurement criteria as ourselves, and Vayner et al [4], using the measurement criteria of Puylaert [5], who observed enlarged MLNs only rarely in asymptomatic children (4% and 9%, respectively).
We found enlarged MLNs in 28.3% of the asymptomatic children who underwent abdominal and pelvic CT after sustaining abdominal trauma. These results are in contrast to those reported by Macari et al [6] who found no enlarged MLNs in any of 60 adult patients examinated after abdominal trauma by CT.
In conclusion, our data suggest that the presence of enlarged MLNs with a longitudinal diameter of more than 4 mm but less than 20 mm in children of all ages and both sexes is a relatively common non-specific and usually non-pathological finding.
Received for publication March 17, 2003.
Revision received August 6, 2004.
Accepted for publication September 17, 2004.
|
References
|
|---|
- Sivit CJ, Newman KD, Chandra RS. Visualization of enlarged lymph nodes at US examination. Pediatr Radiol 1993;23:471–5.[CrossRef][Medline]
- Watanabe M, Ishii E, Hirowatari Y, Hayashida Y, Koga T, Akazawa K, et al. Evaluation of abdominal lymphadenopathy in children by ultrasonography. Pediatr Radiol 1997;27:860–4.[CrossRef][Medline]
- Healy MV, Graham PM. Assessment of abdominal lymph nodes in a normal paediatric population: an ultrasound study. Australian Radiol 1993;37:171–2.
- Vayner N, Coret A, Polliack G, Weiss B, Hertz M. Mesenteric lymphadenopathy in children examinated by US for chronic and/or recurrent abdominal pain. Pediatr Radiol 2003;33:864–7.[CrossRef][Medline]
- Puylaert JB. Mesenteric adenitis and acute terminal ileitis. US evaluation using graded compression. Radiology 1986;161:691–5.[Abstract/Free Full Text]
- Macari M, Hines J, Balthazar E, Megibow A. Mesenteric adenitis: CT diagnosis of primary versus secondary causes, incidence and clinical significance in pediatric and adult patients. AJR Am J Roentgenol 2002;178:853–8.[Abstract/Free Full Text]
- Rao PM, Rhea JT, Novelline RA. CT diagnosis of mesenteric adenitis. Radiology 1997;202:145–7.[Abstract/Free Full Text]
- Birnbaum BA, Jeffrey RB Jr. CT and sonographic evaluation of acute right lower quadrant pain. AJR Am J Roentgenol 1998;170:361–73.[Free Full Text]
Top
Abstract
Introduction
