Intestinal lymphangiectasia is a malabsorption disorder Overview of Malabsorption Malabsorption is inadequate assimilation of dietary substances due to defects in digestion, absorption, or transport. Malabsorption can affect macronutrients (eg, proteins, carbohydrates, fats)... read more .
Malformation of the lymphatic system is congenital or acquired. Congenital cases usually manifest in children (typically diagnosed before age 3 years) and less frequently in adolescents or young adults. Males and females are equally affected. In acquired cases, the defect may be secondary to retroperitoneal fibrosis, constrictive pericarditis, pancreatitis, neoplastic tumors, and infiltrative disorders that block the lymphatics.
Impaired lymphatic drainage leads to increased pressure and leakage of lymph into the intestinal lumen. Impairment of chylomicron and lipoprotein absorption results in malabsorption of fats and protein. Because carbohydrates are not absorbed through the lymphatic system, their uptake is not impaired.
Early manifestations of intestinal lymphangiectasia include massive and often asymmetric peripheral edema, intermittent diarrhea, nausea, vomiting, and abdominal pain. Some patients have mild to moderate steatorrhea (foul-smelling, pale, bulky, and greasy stools). Chylous pleural effusions (chylothorax) and chylous ascites may be present. Growth is retarded if onset is in the first decade of life.
Diagnosis of intestinal lymphangiectasia usually requires endoscopic small-bowel biopsy, which shows marked dilation and ectasia of the mucosal and submucosal lymphatic vessels at the tips of the villi. Alternatively, contrast lymphangiography (injection of contrast material via the pedal lymphatics) can show abnormal intestinal lymphatics.
Laboratory abnormalities include lymphocytopenia and low levels of serum albumin, cholesterol, IgA, IgM, IgG, transferrin, and ceruloplasmin.
Barium studies may show thickened, nodular mucosal folds that resemble stacked coins. D-xylose absorption is normal. Intestinal protein loss can be shown by using chromium-51–labeled albumin.
Abnormal lymphatics cannot be corrected. Supportive treatment of intestinal lymphangiectasia includes a low-fat (< 30 g/day), high-protein diet containing medium-chain triglyceride supplements. Supplemental calcium and fat-soluble vitamins are given.
Intestinal resection or anastomosis of the abnormal lymphatics to the venous channels may be beneficial. Pleural effusions should be drained by thoracentesis.