Intermesenteric appendicular abscess, a diagnostic challenge; case report and review.

Area of Science:

• Gastroenterology
• Surgical Pathology

Background:

• Intermesenteric abscesses of appendiceal origin are infrequently diagnosed preoperatively.
• Atypical clinical manifestations and limited sensitivity of diagnostic imaging contribute to delayed diagnosis.

Observation:

• A 43-year-old male presented with epigastric pain, emesis, and leukocytosis, initially showing unremarkable abdominal radiography, ultrasound, and endoscopy.
• Subsequent radiography revealed abdominal distension and ileus. Computed tomography (CT) demonstrated mesenteric edema, a small fluid collection with extraluminal air, and adjacent paretic loops, but was inconclusive.
• A barium enema was normal. The patient developed fever, worsening pain, and an abdominal mass, necessitating laparotomy.

Findings:

• Laparotomy revealed a large intermesenteric abscess secondary to perforated gangrenous appendicitis.
• Appendectomy was performed with a normal surgical outcome.

Implications:

• A high index of suspicion for appendiceal-origin intermesenteric abscess should be raised with atypical presentations such as fever, ileus, or a tender abdominal mass.
• Specific CT findings, including abscess, extraluminal air, and ileus, are crucial indicators.