Intestinal lymphangiectasia

Intestinal lymphangiectasia is a rare disorder characterized by dilatation of intestinal lymphatic vessels, which can lead to protein-losing enteropathy. It may be primary (congenital; also known as Waldmann disease) or secondary to conditions that impair lymphatic flow, such as cardiovascular disorders, neoplasms, or infections. The underlying pathophysiology involves the leakage of chyle into the intestinal lumen, resulting in the loss of proteins, lymphocytes, and lipids. The primary clinical feature is peripheral edema, typically in the lower limbs, which is caused by hypoalbuminemia. Other common manifestations include serous effusions, chronic diarrhea, and fatigue. Diagnosis is confirmed by esophagoduodenoscopy (EGD) and duodenal biopsy findings that show dilated lymphatic vessels. Management is based on dietary modification with a strict low-fat, high-protein diet supplemented with medium-chain triglycerides (MCTs) and fat-soluble vitamins. Pharmacological options such as octreotide or mTOR inhibitors may be considered in rare cases refractory to dietary modification. Surgical or interventional therapies are reserved for focal disease.

Intestinal lymphangiectasia is classified as primary or secondary. ^[1][2]

• Primary intestinal lymphangiectasia: usually congenital or idiopathic, resulting from developmental abnormalities of intestinal lymphatic vessels
• Secondary intestinal lymphangiectasia: develops secondary to conditions that obstruct or damage intestinal lymphatic drainage

Primary intestinal lymphangiectasia ^[3]

• No identifiable cause
• Rare genetic forms have been reported in association with certain syndromes (e.g., Turner syndrome).

Secondary intestinal lymphangiectasia ^[2][3]

• Cardiovascular
  • Constrictive pericarditis
  • Chronic heart failure
  • Postsurgical cardiac venous hypertension (e.g., Fontan procedure)
  • Central venous thrombosis (e.g., superior vena cava, subclavian)
• Neoplastic
  • Intestinal lymphoma
  • Neuroblastoma
  • Multiple myeloma
  • Waldenstrom macroglobulinemia
• Infectious
  • Whipple disease
  • Intestinal tuberculosis
  • Viral: HIV, CMV, rotavirus
  • Parasitic: Giardia duodenalis
• Inflammatory and autoimmune
  • Crohn disease
  • Sarcoidosis
  • Sjogren syndrome
  • Systemic sclerosis
• Infiltrative: amyloidosis
• Iatrogenic: retroperitoneal fibrosis (e.g., post-radiation)

Primary intestinal lymphangiectasia is usually a childhood disease, while secondary forms more often occur in adults.

• Peripheral edema (especially lower limbs)
• Serous effusions (pleural, pericardial, and/or peritoneal)
• Chronic diarrhea
• Constitutional symptoms (e.g., fatigue)

General principles ^[1][3]

• Diagnosis is confirmed by EGD with duodenal biopsies.
• Disease distal to the suspensory muscle of duodenum is evaluated with capsule endoscopy.
• Laboratory studies show findings that support protein-losing enteropathy.
• Additional imaging (e.g., echocardiography, abdominal CT) is used to evaluate secondary causes.

Secondary causes of lymphatic obstruction (e.g., malignancy, infection, cardiac disease) should be excluded before diagnosing primary intestinal lymphangiectasia.

Endoscopy ^[1][3]

• EGD with duodenal biopsies
  • Indication: initial investigation to visualize mucosal lesions and obtain tissue samples
  • Findings
    • Macroscopic: yellow-brown or milky mucosal elevations
    • Histopathologic: dilated lymphatic vessels in the mucosa and submucosa
• Capsule endoscopy
  • Indication: to determine the extent of disease below the ligament of Treitz
  • Findings: whitish, flat or raised spots on the mucosa, which may coalesce

Imaging ^[1][3]

• MR lymphangiography
  • Indication: to assess lymphatic anatomy and flow, determine the extent of disease, and guide treatment
  • Findings: visualizes lymphatic channels and areas of dilatation
• Abdominal CT: for secondary causes such as external compression
• Echocardiogram: to evaluate for cardiac causes (e.g., constrictive pericarditis)

Laboratory studies ^[1][3]

• Blood tests
  • Hypoproteinemia, particularly marked hypoalbuminemia
  • Normal or mildly decreased prealbumin levels ^[3]
  • Hypogammaglobulinemia
  • Lymphopenia
• Stool tests: increased α1-antitrypsin clearance

• Whipple disease
• Intestinal lymphoma
• Crohn disease
• Intestinal tuberculosis
• Giant hypertrophic gastritis
• Eosinophilic gastritis

The differential diagnoses listed here are not exhaustive.

Management is guided by the response to dietary therapy and extent of disease. ^[1][3]

• Dietary therapy
  • Mainstay of treatment
  • Content: low-fat, high-protein diet
  • Supplementation: MCTs, essential fatty acids, and fat-soluble vitamins
• Pharmacological management
  • Consider for diffuse disease refractory to dietary modification.
  • Options include:
    • Somatostatin analogues (e.g., octreotide)
    • mTOR inhibitors (e.g., sirolimus, everolimus)
• Interventional or surgical therapy
  • Consider for focal disease refractory to dietary modification.
  • Options include:
    • Segmental intestinal resection
    • Lymphatic embolization
• Supportive care
  • Nutritional support and correction of fluid-electrolyte losses
  • Albumin infusions: for severe hypoalbuminemia
  • Diuretics: for symptomatic edema or effusions
  • Immunoglobulin replacement: for profound hypogammaglobulinemia with recurrent infections

• Nutritional deficiencies due to fat malabsorption
  • Deficiencies of fat-soluble vitamins and essential fatty acids
  • Osteomalacia due to vitamin D deficiency
• Immunologic abnormalities (e.g., hypogammaglobulinemia, lymphopenia) may lead to recurrent infections.
• Increased risk of non-Hodgkin lymphomas
• Hepatic fibrosis

We list the most important complications. The selection is not exhaustive.