Epiploic appendagitis: An overlooked cause of acute abdominal pain

Table 1 Risk factors for primary epiploic appendagitis

Risk factor	Explanation
Obesity	Increased visceral fat enlarges epiploic appendages, predisposing them to torsion
Large or elongated epiploic appendages	Anatomical variations can increase the risk of pedicle twisting
Sudden or vigorous physical activity	Rapid body movements may induce torsion of appendages
Male gender	A higher prevalence is reported in men, with a ratio of up to 4:1 compared to women
Middle age (30-50 years)	Most cases occur during the fourth and fifth decades of life
Increased intra-abdominal pressure	Includes straining during constipation, heavy lifting, chronic coughing, or other causes of pressure spikes

Table 2 Comparison of primary and secondary epiploic appendagitis

Feature	Primary epiploic appendagitis	Secondary epiploic appendagitis
Definition	Isolated inflammation of an epiploic appendage	Inflammation of an epiploic appendage secondary to adjacent organ inflammation
Etiology	Torsion or spontaneous venous thrombosis causing ischemic infarction	Extension of inflammation from nearby pathology (e.g., diverticulitis, appendicitis, cholecystitis)
precipitating factors	Large, elongated appendages; obesity; sudden body movements	Underlying intra-abdominal infection or inflammation
clinical presentation	Localized, non-radiating abdominal pain; minimal systemic symptoms	Symptoms dominated by the underlying primary disease
imaging findings	Isolated inflamed epiploic appendage with minimal adjacent tissue involvement	Inflamed appendage plus significant adjacent inflammatory changes
Management	Conservative treatment (NSAIDs, observation)	Treatment of the underlying primary condition
Prognosis	Excellent; self-limiting within 1-2 weeks	Depends on resolution of the primary disease

NSAID: Nonsteroidal anti-inflammatory drug.

Table 3 Clinical pearls

Clinical pearls
Sudden, localized, non-radiating abdominal pain without significant systemic symptoms raises concern for epiploic appendagitis
Minimal laboratory abnormalities help differentiate it from more prominent inflammatory processes like diverticulitis or appendicitis
Imaging (especially CT) is critical for diagnosis; ultrasound can suggest the diagnosis, particularly in thin patients, but CT remains the gold standard, providing definitive findings to distinguish epiploic appendagitis from other causes of acute abdominal pain
Most cases resolve conservatively without the need for surgery

CT: Computed tomography.

Table 4 Comparison of radiologic modalities in the diagnosis of epiploic appendagitis

Feature	Ultrasound	Computed tomography	Magnetic resonance imaging
Utility	First-line in young, thin patients; pregnancy; bedside availability	Gold standard; most widely used modality	Alternative when CT is contraindicated (e.g., pregnancy, allergy to contrast)
Key imaging features	Hyperechoic, non-compressible ovoid mass; no Doppler flow; mild surrounding edema	Oval fat-density lesion with hyperattenuating rim (“ring sign”) and central dot sign	T1-hyperintense lesion with T2-hyperintense rim; no contrast enhancement
Sensitivity/specificity	Operator-dependent; moderate sensitivity and specificity	High sensitivity and specificity (> 90%)	Comparable to CT in skilled hands; limited data
Advantages	No radiation; portable; repeatable	High resolution; widely available; detailed fat and bowel wall visualization	Excellent soft tissue contrast; radiation-free
Limitations	May be limited by obesity or bowel gas; user expertise critical	Radiation exposure; contrast may be needed	High cost; limited availability; longer scan time
Preferred use	Initial screening in selected populations (e.g., pediatrics, pregnant women)	Routine evaluation of acute abdominal pain	Problem-solving tool or radiation-sensitive patients

CT: Computed tomography.

Table 5 Expanded differential diagnoses of epiploic appendagitis

Condition	Typical pain location	Key symptoms	Imaging findings	Distinguishing features
Primary epiploic appendagitis	Left or right lower quadrant	Localized, constant, dull pain without systemic symptoms	Oval fat-density lesion adjacent to colon; “ring and dot” signs on CT	Minimal systemic signs; resolves spontaneously; no significant bowel wall thickening
Acute diverticulitis	Most often left lower quadrant (sigmoid colon)	Abdominal pain, fever, bowel habit changes (constipation or diarrhea), ± urinary symptoms	Colonic wall thickening, pericolic fat stranding, diverticula on CT	Older age, significant leukocytosis, risk of perforation, and abscess
Acute appendicitis	Right lower quadrant	Migratory pain (from periumbilical to RLQ), anorexia, nausea, vomiting, fever	Enlarged appendix (> 6 mm), wall thickening, periappendiceal fat stranding, appendicolith	Younger age; systemic signs; typical migratory pain pattern
Acute omental infarction	More or less central abdomen (medial to cecum or ascending colon)	Localized pain; less frequent systemic symptoms	Larger, cake-like fatty mass centered in omentum, medial to colon	Lesion size > 5 cm; central location in omentum
Mesenteric lymphadenitis	Right lower quadrant	Abdominal pain, often post-infectious; fever	Enlarged mesenteric lymph nodes clustered around mesenteric vessels	Often follows viral illness; affects children or young adults
Crohn’s ileitis	Right lower quadrant (terminal ileum)	Abdominal pain, weight loss, low-grade fever, less commonly Chronic diarrhea	Segmental bowel wall thickening, “skip lesions”, mesenteric fat wrapping	Chronic symptoms; associated with extraintestinal manifestations
Infectious ileitis	Right lower quadrant (terminal ileum)	Diarrhea, fever, abdominal pain	Bowel wall thickening, enlarged mesenteric nodes	Recent history of travel or foodborne illness; resolves with antibiotics
Ureteric colic	Flank pain radiating to groin (can mimic RLQ or LLQ pain)	Severe, colicky flank pain, hematuria	Ureteral stone, hydronephrosis on CT or ultrasound	Positive urinalysis for blood; severe intermittent pain
Pelvic inflammatory disease	Bilateral lower abdomen	Lower abdominal pain, fever, abnormal vaginal discharge	Thickened, fluid-filled fallopian tubes on pelvic ultrasound	Cervical motion tenderness; positive pelvic exam findings
Ovarian torsion	Lateral pelvic pain	Sudden-onset severe pelvic pain, nausea, vomiting	Enlarged ovary, peripheral follicles, absent Doppler flow	Surgical emergency; Doppler ultrasound critical for diagnosis
Ruptured or hemorrhagic ovarian cyst	Lateralized pelvic pain	Sudden unilateral lower abdominal pain, sometimes following exertion	Free pelvic fluid, complex adnexal mass on ultrasound	May self-resolve or cause hemoperitoneum depending on severity
Ectopic pregnancy	Any lower quadrant or pelvic pain	Amenorrhea, vaginal bleeding, abdominal pain	Empty uterus, adnexal mass on transvaginal ultrasound; positive 2-hCG	Suspected in reproductive-age women; obstetric emergency if ruptured

RLQ: Right lower quadrant; LLQ: Left lower quadrant; 2-hCG: 2-human chorionic gonadotropin; CT: Computed tomography.