What are the differential diagnoses (DDs) for multiple small vascular ectatic lesions in the small bowel?

Differential Diagnoses for Multiple Small Vascular Ectatic Lesions in the Small Bowel

The primary differential diagnoses for multiple small vascular ectatic lesions in the small bowel include angioectasias (angiodysplasias), Dieulafoy lesions, arteriovenous malformations, and less commonly, small bowel neoplasms or vasculitic lesions.

Primary Vascular Lesions

Angioectasias (Angiodysplasias)

• Most common vascular lesion causing small bowel bleeding, particularly in patients over 60 years of age 1
• Appear as red, fern-like flat lesions consisting of ectatic blood vessels radiating from a central feeding vessel, typically 2-10 mm in diameter 1
• Venous lesions that present with punctulate erythema (<1 mm) or patchy erythema (few mm), with or without oozing 2
• Can be found throughout the small intestine but typically present with iron-deficiency anemia and occult bleeding rather than massive hemorrhage 1
• Diagnostic yield of 20-40% when small bowel evaluation is performed for iron deficiency anemia 1

Dieulafoy Lesions

• Arterial lesions characterized by punctulate lesions (<1 mm) with pulsatile bleeding, or pulsatile red protrusions without surrounding venous dilatation 2
• More common in younger patients compared to angioectasias 1
• Most conspicuous on arterial phase imaging during multiphase CT enterography 1
• Require different treatment approach (clipping) compared to venous lesions 2

Arteriovenous Malformations

• Present as pulsatile red protrusions with surrounding venous dilatation, distinguishing them from Dieulafoy lesions 2
• May cause arterial bleeding requiring clipping or surgical intervention 2
• Can be detected on multiphase CT enterography with characteristic enhancement patterns 3

Secondary Considerations Based on Clinical Context

Small Bowel Neoplasms

• Small neuroendocrine tumors can present as vascular-appearing lesions, most conspicuous on enteric phase CT enterography 1
• Should be considered when lesions appear mass-like or have atypical features 1

Vasculitic Lesions

• Eosinophilic granulomatosis with polyangiitis (EGPA) can involve small vessels in the gastrointestinal tract with necrotizing vasculitis 1
• Consider when patient has concurrent asthma, eosinophilia, rhinosinusitis, or systemic symptoms 1
• ANCA testing (particularly MPO-ANCA) should be performed if vasculitis is suspected 1
• Other small-vessel vasculitides like granulomatosis with polyangiitis or microscopic polyangiitis are less likely but should be considered with appropriate clinical context 1

NSAID-Induced Lesions

• NSAID-related disease can cause sharply demarcated ulcers with predilection for terminal ileum and proximal colon 1
• Multiple diaphragm-like strictures with normal intervening mucosa are pathognomonic 1

Ischemic Lesions

• Non-occlusive ischemia typically involves watershed areas but can present with vascular-appearing lesions 1
• Consider in patients with cardiovascular disease or hypotension 4

Diagnostic Approach Algorithm

Initial evaluation:

• Perform capsule endoscopy as the investigation of choice for suspected small bowel vascular lesions after negative EGD and colonoscopy 1
• Multiphase CT enterography can classify lesions into angioectasias, arterial lesions, or venous abnormalities based on enhancement patterns 1, 3

Key distinguishing features:

• Venous lesions (angioectasias): Non-pulsatile, flat, fern-like appearance without active arterial bleeding 1, 2
• Arterial lesions: Pulsatile bleeding, protrusion, visible on arterial phase imaging 1, 2
• Vasculitis: Systemic symptoms, eosinophilia, ANCA positivity, multiple organ involvement 1

Critical Pitfalls to Avoid

• Do not assume all small bowel vascular lesions are angioectasias - arterial lesions require different hemostatic approaches (clipping vs. cauterization) 2
• Angioectasias are frequently found in asymptomatic patients - determining hemorrhagic causality can be difficult when lesions are not actively bleeding 5
• Rebleeding rate for small bowel angioectasias is 45% despite therapy, higher than colonic lesions due to incomplete visualization 1
• Consider systemic conditions: cardiac disease, chronic kidney disease, and von Willebrand disease are associated with angioectasias 4
• Always exclude celiac disease in patients with iron deficiency anemia, as it is present in 2-6% of cases and may coexist with vascular lesions 1