Basics
Description
Mesenteric adenitis is defined as inflammation of the mesenteric lymph nodes. The inflamed nodes are usually clustered in the right lower quadrant (RLQ) small bowel mesentery or are located ventral to the psoas muscle.
Epidemiology
- Age related, most common in patients <15 years of age
- Affects males and females equally
- History of recent sore throat or upper respiratory tract infection found in 20 " 30% of subjects
- Most common cause of acute abdominal pain in young adults and children
- Self-limiting condition
- Most common cause of inflammatory adenopathy (more common than tuberculosis)
- Mesenteric adenitis in childhood is related to a decreased risk of ulcerative colitis in adulthood.
Pathophysiology
- Lymph nodes involved are those draining the ileocecal area. Lymph nodes absorb toxic products or bacterial products secondary to stasis.
- Nodes are enlarged up to 10 mm; discrete, soft, and pink; and with time become firm. Calcification and suppuration are rare.
- Cultures of the nodes are negative.
- Reactive hyperplasia: Adenitis results from a reaction to some material absorbed from the small intestine, reaching the intestine from the blood or lymphatic system.
- Hypersensitivity reaction to a foreign protein
Etiology
- Viral
- Adenovirus, echovirus 1 and 14, coxsackieviruses, Epstein-Barr virus (EBV), cytomegalovirus (CMV), human immunodeficiency virus (HIV)
- Bacterial
- Tuberculosis, Streptococcus species, Staphylococcus species, Escherichia coli, Yersinia enterocolitica, Bartonella henselae (cat-scratch disease)
Diagnosis
Can be difficult to differentiate from acute appendicitis clinically, and many patients may undergo laparotomy before diagnosis
History
- Abdominal pain
- Dull ache as well as colicky pain occurs due to stretch on the mesentery.
- May initially be in the upper abdomen/RLQ or generalized
- If generalized, eventually becomes localized to RLQ
- Patients often have difficulty localizing the exact point of the most intense pain, in contrast to appendicitis, where pain is often localized to RLQ.
- Intermittent spasms: Between spasms, the patient feels well.
- Signs and symptoms:
- Abdominal pain (RLQ)
- Anorexia and fatigue are common.
- Nausea and vomiting usually precede abdominal pain.
- Fever
- Diarrhea
Physical Exam
- Often febrile to >38 °C (100.4 °F)
- May have associated upper respiratory tract infection symptoms, such as rhinorrhea or hyperemic pharynx
- Presence of peripheral lymphadenopathy
- Abdominal examination
- Tenderness of the RLQ: may be a little higher, more medial, and less severe than acute appendicitis
- Point of maximal tenderness may vary from one examination to the next.
- Voluntary guarding with or without rebound tenderness and without rigidity
- Rectal tenderness
Diagnostic Tests & Interpretation
- Mesenteric adenitis is a diagnosis of exclusion.
- It can only be diagnosed accurately at laparoscopy or laparotomy.
- Ultrasound or CT scan may demonstrate enlarged mesenteric lymph nodes.
- See "Differential Diagnosis. "
Lab
Complete blood count and C-reactive protein may be increased but are not specific.
Imaging
- Abdominal ultrasound
- Differentiates among acute appendicitis, pelvic inflammatory disease, ovarian pathology, and mesenteric adenitis
- Contrast-enhanced CT scan of the abdomen and pelvis shows enlarged mesenteric lymph nodes, with possible ileal or ileocecal wall thickening, normal appendix
- MRI
Diagnostic Procedures/Other
- Laparoscopic surgery
- Laparotomy
Differential Diagnosis
- Infection
- Acute appendicitis: 20% of patients treated for possible acute appendicitis had mesenteric adenitis.
- Infectious mononucleosis: associated lymphadenopathy more generalized
- Associated splenomegaly: can screen for positive EBV titers
- Tuberculosis: associated intestinal involvement, positive purified protein derivative (PPD) test, elevated erythrocyte sedimentation rate (ESR)
- Pelvic inflammatory disease: should be considered in sexually active adolescents, and pelvic exam may be helpful
- Urinary tract infections/pyelonephritis: Urinalysis and urine culture are helpful.
- Abscess: related to missed acute appendicitis or inflammatory bowel disease (IBD)
- Y. enterocolitica infection: bloody diarrhea, arthropathy present; stool culture is diagnostic.
- Typhlitis: Transmural inflammation of the cecum is seen in patients with neutropenia
- Tumors
- Lymphoma: Adenopathy can be more generalized.
- CT scan of the abdomen and/or laparotomy to confirm the diagnosis
- Trauma
- Hematomas of the abdominal wall and intestines
- History of trauma
- Metabolic
- Acute intermittent porphyria
- Cyclic episodes of acute abdominal pain and vomiting
- Appropriate metabolic workup diagnostic
- Congenital
- Duplication cysts: may present with abdominal pain due to rupture, bleeding, intussusception, or volvulus
- Meckel diverticulum: may present with diverticulitis or act as a lead point for intussusception
- Miscellaneous
- Crohn disease: associated mesenteric adenitis and intestinal involvement
- Intussusception: acute abdominal pain with "currant jelly " stools; barium/air enema is diagnostic and therapeutic.
- Ovarian cysts: may need abdominal/pelvic ultrasound to differentiate between the two
- Chronic mesenteric ischemia
Treatment
Most patients recover completely without any specific treatment.
Ongoing Care
Follow-up Recommendations
Patient Monitoring
Watch for
- Increasing abdominal pain
- Vomiting
- Fevers
- Toxic appearance
- Severe tenderness that is persistent
- Guarding
- Rigidity
- Decreasing bowel sounds
Prognosis
- Most patients recover completely without any specific treatment.
- When to expect improvement: Acute symptoms may take days to resolve and generally last a few days after the associated viral symptoms have resolved.
Complications
- Suppuration
- Intussusception (enlarged lymph nodes can be a lead point for intussusception)
- Rupture of lymph nodes
- Abscess formation
- Peritonitis
- Death (very rare) from abscess and peritonitis
Additional Reading
- Carty HM. Paediatric emergencies: non-traumatic abdominal emergencies. Eur Radiol. 2002;12(12):2835 " 2848. [View Abstract]
- Frisch M, Pedersen BV, Andersson RE. Appendicitis, mesenteric lymphadenitis, and subsequent risk of ulcerative colitis: cohort studies in Sweden and Denmark. BMJ. 2009;338:b716. [View Abstract]
- Karmazyn B, Werner EA, Rejaie B, et al. Mesenteric lymph nodes in children: what is normal? Pediatr Radiol. 2005;35(8):774 " 777. [View Abstract]
- Lucey BC, Stuhlfaut JW, Soto JA. Mesenteric lymph nodes seen at imaging: causes and significance. Radiographics. 2005;25(2):351 " 365. [View Abstract]
- Macari M, Balthazar EJ. The acute right lower quadrant: CT evaluation. Radiol Clin North Am. 2003;41(6):1117 " 1136. [View Abstract]
- Macari M, Hines J, Balthazar E, et al. Mesenteric adenitis: CT diagnosis of primary versus secondary causes, incidence, and clinical significance in pediatric and adult patients. AJR Am J Roentgenol. 2002;178(4):853 " 858. [View Abstract]
- Toorenvliet B, Vellekoop A, Bakker R, et al. Clinical differentiation between acute appendicitis and acute mesenteric adenitis in children. Eur J Pediatr Surg. 2011;21(2):120 " 123. [View Abstract]
- Zeiter DK, Hyams JS. Recurrent abdominal pain in children. Pediatr Clin North Am. 2002;49(1):53 " 71. [View Abstract]
Codes
ICD09
- 289.2 Nonspecific mesenteric lymphadenitis
ICD10
- I88.0 Nonspecific mesenteric lymphadenitis
SNOMED
- 267548000 Nonspecific mesenteric adenitis
- 234090004 Tuberculous mesenteric adenitis (disorder)
- 49631001 Acute mesenteric adenitis
- 191377002 Chronic mesenteric lymphadenitis (disorder)
FAQ
- Q: Can one differentiate clinically between acute appendicitis and nonspecific mesenteric adenitis?
- A: Yes, but the differences can be subtle. Patients with nonspecific mesenteric adenitis generally cannot localize the exact point of the most intense pain, unlike those with appendicitis, who can localize their pain to the RLQ. Abdominal examination in patients with mesenteric adenitis is characterized by increased tenderness of the RLQ that is a little higher, more medial, and less severe than that in acute appendicitis. Point of maximal tenderness may vary between examinations in patients with nonspecific mesenteric adenitis. There is no rigidity on abdominal examination in patients with nonspecific mesenteric adenitis. However, it is clinically difficult to differentiate the two entities.
- Q: Which investigations can be diagnostic for RLQ pain?
- A: An ultrasound or CT scan of the RLQ can differentiate between acute appendicitis, ovarian pathology, and lymphadenopathy. An upper gastrointestinal series with small bowel follow-through or a magnetic resonance enterography study can be diagnostic for IBD.