Case discussion
01Clinical context
A middle-aged female presented with lower abdominal pain. Contrast-enhanced CT of the abdomen and pelvis was performed to evaluate suspected acute intra-abdominal inflammation.
02Key imaging findings
CT shows a markedly dilated appendix measuring about 13–14 mm with mural thickening and enhancement. There is marked periappendiceal fat stranding and a small, rim-enhancing fluid collection measuring approximately 14 × 10 mm adjacent to the proximal appendix, consistent with a contained perforation and a small periappendiceal abscess. Mild reactive thickening of adjacent caecum and distal small bowel loops, small reactive mesenteric lymph nodes, and mild prominence of the distal right ureter are also noted. No free intraperitoneal air or distant collections are seen.
03Diagnostic reasoning
The diagnosis was established on contrast-enhanced CT by identifying a dilated, enhancing appendix with mural thickening and surrounding fat stranding. The key discriminator was the small rim-enhancing fluid collection adjacent to the proximal appendix, indicating a contained perforation with abscess formation. Absence of free intraperitoneal air was noted, emphasizing that perforation can be sealed by adjacent tissues. Additional reactive changes in adjacent bowel and lymph nodes supported the inflammatory process. Treatment and clinical outcome were not supplied.
04Questions for clinical practice
Does absence of free intraperitoneal air exclude perforation?
No. Perforation can be contained by adjacent tissues.
Why does a periappendiceal abscess matter?
It indicates complicated appendicitis and should be communicated promptly to the treating team.
Does a small abscess automatically require drainage?
No. Treatment depends on clinical condition, collection characteristics and specialist assessment.
Is the outcome known?
Treatment and follow-up outcome were not supplied.
05Teaching point
This case highlights that appendiceal perforation may be contained without free intraperitoneal air, and that even a small periappendiceal abscess confirms complicated appendicitis. Careful CT evaluation for focal fluid collections and periappendiceal inflammatory changes is essential to guide appropriate clinical management, especially in older patients where follow-up is important to exclude neoplasm.
Shown for education. De-identified — no identifiable patient data. A radiology report is a specialist opinion and must be read with the full clinical context by the treating physician.