1. Etiology

• a Postenterocyte Event resulting in malabsorption
• any disorder which impairs lymph flow so that the secretory vesicles of fat extruded from the enterocytes and taken up by the mesenteric lymphatics are unable to be transferred to the bloodstream

1. Gastrointestinal Manifestations

• malabsorption with steatorrhea
• protein-loosing enteropathy
  • edema is the major clinical manifestation

1. For Malabsorption

• see "Malabsorptive Disorders"
• especially of fat, protein, fat-soluble vitamins
• stool - increased fat, protein, and lymphocytes

2. Diagnosis

• elevated fecal alpha-1-antitrypsin levels (> 1 mg/g of dry stool) - acts as a marker for protein-loosing enteropathies

3. Serum

• hypoproteinemia
• hypogammaglobulinemia
• lymphocytopenia

4. Biopsy - Duodenum

• obtain during fasting
• patchy changes in the small bowel mucosa represent multiple punctate lesions in the proximal duodenum
• biopsies demonstrate widely dilated lacteals within the villi
• ruptured mucosal lacteals will leak lymph into the intestinal lumen resulting in protein and fat loss in the stool along with lymphocytes
• absorptive function is usually intact except for long-chain fats and fat-soluble vitamins

1. Treat Underlying Condition

• medical or surgical decompression of the lymphatics

2. Diet

• principle to decrease the intestinal lymphatic pressure
• reduce long-chain fats in diet
• add medium-chain triglycerides (transported by portal stream)
• elemental diets with very low fat content

3. Supportive

• nutritional and vitamin supplementation
  • especially fat-soluble vitamins