What is the diagnosis and management for a duodenal biopsy showing white spots, dilated lacteals (lymphatic vessels), and dilated lymphatics?

Diagnosis: Primary Intestinal Lymphangiectasia

The duodenal biopsy findings of white spots and dilated lacteals are pathognomonic for intestinal lymphangiectasia, a protein-losing enteropathy caused by obstruction of intestinal lymphatic drainage. 1, 2

Clinical Confirmation

The diagnosis is established through the constellation of:

• Endoscopic findings: White opaque spots on duodenal mucosa representing dilated lacteal vessels 1, 3
• Histopathology: Massively dilated lamina propria lymphatics and dilated lacteals distorting villus architecture 1, 4, 2
• Laboratory confirmation: Elevated 24-hour stool alpha-1-antitrypsin clearance documenting intestinal protein loss 1, 2
• Expected biochemical abnormalities: Hypoalbuminemia, hypogammaglobulinemia, and lymphopenia 1, 4, 2

Important caveat: This is NOT celiac disease—the dilated lacteals and white spots are distinct from the villous atrophy, crypt hyperplasia, and increased intraepithelial lymphocytes seen in celiac disease 5. While villus blunting may occur secondary to lymphatic obstruction, the primary pathology is lymphatic dilation, not immune-mediated enteropathy 1.

Clinical Presentation to Assess

Look specifically for:

• Bilateral lower limb edema (most common presentation, though rarely can be unilateral) 4, 2
• Chronic diarrhea (moderate, not typically severe) 4, 3, 2
• Ascites, pleural effusion, or pericarditis from protein loss 3, 2
• Weight loss or failure to thrive 1, 2
• Fat-soluble vitamin deficiencies (A, D, E, K) 2

Management Algorithm

First-Line Dietary Therapy (Mandatory)

Initiate immediately a high-protein, low-fat diet (<5g fat/day) with medium-chain triglyceride (MCT) supplementation. 1, 4, 2

• MCTs are absorbed directly into portal circulation, bypassing lacteal vessels and preventing lymphatic overload 1, 2
• This dietary control must be permanent; symptoms recur upon withdrawal 2
• Supplement fat-soluble vitamins due to malabsorption 2

Second-Line Pharmacologic Therapy

If dietary modification fails to control symptoms:

• Octreotide (long-acting formulation): Most effective pharmacologic option for refractory cases 3, 2
• Consider antiplasmin or corticosteroids, though evidence is inconsistent 2

Surgical Intervention

Reserve surgical resection only for:

• Segmental, localized disease confirmed on imaging 6, 2
• Failure of medical management with persistent symptoms 6
• Need to exclude underlying malignancy or clarify etiology 6

Critical Long-Term Monitoring

Screen for B-cell lymphoma development—the most serious complication of intestinal lymphangiectasia, which can occur in gastrointestinal tract (stomach, jejunum, ileum) or extra-intestinal sites. 2

Monitor albumin, immunoglobulin levels, and lymphocyte counts at regular intervals to assess treatment response 1, 4, 2

Differential Considerations to Exclude

Rule out secondary causes of lymphatic obstruction:

• Constrictive pericarditis
• Intestinal lymphoma
• Crohn's disease
• Intestinal tuberculosis
• Whipple's disease 2

The presence of white spots with dilated lacteals on both endoscopy and histology makes celiac disease extremely unlikely and should redirect diagnostic focus entirely toward lymphangiectasia. 1, 3