A Spectrum of Entities That May Mimic Abdominopelvic Abscesses Requiring Image-guided Drainage

Abstract

A variety of entities may mimic drainable abscesses. This can lead to misdiagnosis of these entities, unnecessary percutaneous placement of a pigtail drainage catheter, other complications, and delay in appropriate treatment of the patient. Types of entities that may mimic drainable abscesses include neoplasms (lymphoma, gallbladder cancer, gastrointestinal stromal tumor, ovarian cancer, mesenteric fibromatosis, ruptured mature cystic teratoma, recurrent malignancy in a surgical bed), ischemia/infarction (liquefactive infarction of the spleen, infarcted splenule), diverticula (calyceal, Meckel, and giant colonic diverticula), and congenital variants (obstructed duplicated collecting system). Postoperative changes, including expected anatomy after urinary diversion or Roux-en-Y gastric bypass and small bowel resection, may also pose a diagnostic challenge. Nonpyogenic infections (Mycobacterium tuberculosis, Mycobacterium avium complex, echinococcal cysts) and inflammatory conditions such as xanthogranulomatous pyelonephritis and gossypiboma could also be misinterpreted as drainable fluid collections. Appropriate recognition of these entities is essential for optimal patient care. This article exposes radiologists to a variety of entities for which percutaneous drainage may be requested, but is not indicated, and highlights important imaging findings associated with these entities to facilitate greater diagnostic accuracy and treatment in their practice. RSNA, 2018.

Perirectal Abscess and Fistula Secondary to a Fecalith in Rectal Pouch Occurring 51 Years After Duhamel Operation for Hirschsprung’s Disease: Minimally Invasive Treatment

“…A spectrum of entities can mimic abdominopelvic abscesses and it may pose a diagnostic challenge [22]. Types of entities include neoplasms, diverticula, congenital variants, postoperative changes.…”

Image-Guided Percutaneous Drainage of Abdominal Abscesses in Pediatric Patients

“…The borders can be irregular and thicker compared to the thin smooth wall of a simple cyst. The surrounding tissues may show signs of inflammation (e.g., peritoneal fat stranding) or effacement due to the abscess’ mass effect [ 31 ]. Modern CT scanners can provide a fast diagnostic approach without requiring general anesthesia, especially in restless and agitated children, where adequate US examination may be difficult to perform.…”

Imaging Assessment of Ectopic Gas Collections

“…It usually corresponds to surgical material, consisting of gauze fibers left behind during surgery. It can manifest with a wide range of clinical symptoms from being asymptomatic to acute abdominal pain, and complications include fistula formation, bowel obstruction or perforation, and sepsis (20).…”

“…Volume-rendered images help represent the internal whorled configuration (Fig 11b). It is important to be aware of this entity and its classic appearance to prevent misdiagnosis as an ordinary abscess or soft-tissue mass (20).…”