Epiploic appendagitis: An overlooked cause of acute abdominal pain

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.