Differential Diagnosis for 20F with Hematochezia and Isolated 2cm Ulcer in Ileum
The patient presents with hematochezia, and investigations have revealed an isolated 2cm ulcer in the ileum. Here's a categorized differential diagnosis:
- Single most likely diagnosis
- Crohn's disease: This is a strong consideration given the presence of an isolated ulcer in the ileum, which is a common site for Crohn's disease. The disease often presents with gastrointestinal symptoms, including bleeding, and can be diagnosed with a combination of endoscopic, histological, and imaging findings.
- Other Likely diagnoses
- NSAID-induced ulcer: Nonsteroidal anti-inflammatory drugs (NSAIDs) can cause ulcers throughout the gastrointestinal tract, including the small intestine. The patient's age and the presence of an isolated ulcer make this a plausible diagnosis.
- Infectious ileitis (e.g., Yersinia, Salmonella): Infectious causes can lead to ileal ulcers and should be considered, especially if the patient has recently traveled or has been exposed to contaminated food or water.
- Meckel's diverticulum: Although less common, a Meckel's diverticulum with an ulcer could present similarly, especially if it contains gastric mucosa that secretes acid, leading to ulceration.
- Do Not Miss diagnoses
- Intussusception: Although more common in children, intussusception can occur in adults and may cause intestinal obstruction or bleeding. It's crucial to consider this diagnosis due to its potential for serious complications if missed.
- Small bowel tumor (e.g., lymphoma, adenocarcinoma): Although rare, tumors of the small intestine can present with ulcers and bleeding. Given the potential severity of these conditions, they should not be overlooked.
- Rare diagnoses
- Behçet's disease: This rare condition can cause ulcers throughout the gastrointestinal tract, including the ileum, and should be considered if other diagnoses are ruled out and the patient has other systemic symptoms.
- Eosinophilic gastroenteritis: This condition involves eosinophilic infiltration of the gastrointestinal tract and can cause ulcers, among other symptoms. It's a rare diagnosis but should be considered if other tests are inconclusive.
Next Investigation to Order
Given the presence of an isolated ulcer in the ileum, the next best step would be to perform a small bowel follow-through or enteroclysis to further evaluate the small intestine for any other lesions or abnormalities. Additionally, biopsies of the ulcerated area should be taken during the procedure to rule out infectious or neoplastic causes. Blood tests to check for inflammatory markers (e.g., CRP, ESR) and to assess for anemia due to chronic blood loss would also be useful. If Crohn's disease is suspected, serologic tests for perinuclear anti-neutrophil cytoplasmic antibodies (pANCA) or anti-Saccharomyces cerevisiae antibodies (ASCA) may be ordered, although their utility can vary.