For the differential diagnosis of lymphangiectasia, which finding on histopathology would you expect?

• A. Dilated lacteals filled with proteinaceous material
• B. Increased smooth muscle in the lamina propria
• C. Dense neutrophilic infiltrates in the mucosa
• D. Normal villous architecture

Answer: (A)

Lymphangiectasia is defined by dilation of the intestinal lymphatic vessels, the lacteals, within the villi. On histology, you would see markedly dilated lacteals in the lamina propria filled with proteinaceous material (and often fat within them), reflecting leakage of lymph into the gut. This protein loss underlies the typical clinical picture of protein-losing enteropathy. The other histologic patterns don’t fit this process: increased smooth muscle in the lamina propria isn’t characteristic of lymphatic dilation, dense neutrophilic infiltrates point to acute inflammation rather than lymphatic dilation, and while villous architecture might be variably affected, the defining feature is the dilated, protein-filled lacteals.