Differential Diagnosis
The patient's CT scan findings of a linear enhancing tissue tract extending from an ileal loop to an area of focal fat stranding can be approached by considering the following differential diagnoses, categorized for clarity:
Single Most Likely Diagnosis
- Enterocutaneous fistula: This condition is characterized by an abnormal connection between the intestine and the skin, which can occur due to surgical complications, trauma, or diseases like Crohn's. The linear enhancing tissue tract seen on the CT scan is consistent with a fistulous tract, and the presence of infection or abscess (suggested by the focal fat stranding) supports this diagnosis.
Other Likely Diagnoses
- Infected sinus tract: This could be a complication of a surgical procedure or an abscess that has formed a tract to the skin or another organ. The enhancement pattern on CT suggests the presence of a tract that could be infected.
- Iatrogenic injury (e.g., from a surgical or endoscopic procedure): Such injuries can lead to the formation of fistulas or sinus tracts, especially if there was unintended damage to the bowel during a procedure.
Do Not Miss Diagnoses
- Appendicitis with abscess formation: Although the primary finding is related to the ileal loop, appendicitis can sometimes present with atypical locations of pain or abscess formation, especially if the appendix is retrocecal. Missing this diagnosis could lead to severe consequences if not promptly treated.
- Diverticulitis with abscess: While more commonly associated with the sigmoid colon, diverticulitis can occur in the small intestine (Meckel's diverticulum) and could potentially present with similar imaging findings.
Rare Diagnoses
- Gastrointestinal stromal tumor (GIST) with fistula formation: Although rare, a GIST could potentially erode into adjacent structures, forming a fistula. The imaging findings might not be typical for a GIST, but it's a consideration in the differential diagnosis.
- Actinomycosis: This is a rare bacterial infection that can cause sinus tracts and fistulas, often in the context of bowel disease or recent surgery. It's an uncommon condition but should be considered in the appropriate clinical context.