Background
Intestinal lymphangiectasia is a rare protein-losing gastroenteropathy characterized by dilatation of the intestinal lymphatics and loss of lymph fluid into the gastrointestinal tract, leading to the development of hypoproteinemia, edema, lymphocytopenia, hypogammaglobinemia, and immunologic anomalies. [1]
Traditionally, protein-losing gastroenteropathies have been classified into three groups (depending on the mechanism of their etiology) that include the following [2] : (1) those causing mucosal damage leading to increased permeability to protein (usually not involving mucosal ulcerations), (2) those with mucosal erosions and/or ulcerations, and (3) those in which protein loss is secondary to mechanical lymphatic obstruction.
Although a more detailed discussion on protein-losing enteropathy is presented in another article, this article specifically addresses intestinal lymphangiectasia.
Pathophysiology
Intestinal lymphangiectasia is a rare, benign disease characterized by hypoproteinemia, edema, and lymphocytopenia, resulting from focal or diffuse dilatation of intestinal mucosal, submucosal, and subserosal lymphatics and loss of lymph fluid into the gastrointestinal (GI) tract. [3, 4] This leads to immunologic abnormalities, including hypogammaglobulinemia, anergy, and impaired allograft rejection. In addition to the loss of other serum components (eg, lipids), iron and certain trace metals may also be affected. [4]
Etiology
The following conditions can cause intestinal lymphangiectasia:
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Abdominal or retroperitoneal carcinoma
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Cardiac diseases (eg, constrictive pericarditis, congestive heart syndrome)
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Mesenteric tuberculosis
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Retroperitoneal fibrosis
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Intestinal endometriosis
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Sclerosing mesenteritis
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Lymphenteric fistula
Epidemiology
United States data
The United States and international frequency of intestinal lymphangiectasia is unknown.
Race-, sex-, and age-related demographics
No racial predilection exists. However, there is a male-to-female ratio of 3:2.
Intestinal lymphangiectasia can be primary (ie, congenital), in which case it affects children and young adults (mean age of onset, 11 y). The diagnosis in these cases often occurs during the first decade of life, with the first manifestations being persistent diarrhea and peripheral edema. This condition can also be secondary to other disease states, thereby affecting older adults. [1, 5] In a series from Japan, the average age at onset was 22.9 years.
Prognosis
The clinical course of intestinal lymphangiectasia is highly variable with about 23% of patients showing improvement and 64% remaining unchanged; the mortality rate is 13%.
For patients with primary intestinal lymphangiectasia with an onset early in life (usually during the first decade), growth retardation usually occurs. The prognosis of patients with secondary intestinal lymphangiectasia depends on the extent and severity of the underlying disease.
Morbidity/mortality
Morbidity is related to the pathophysiology of this disease. Edema and diarrhea are predominant clinical features; however, the following negative sequelae are also observed:
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Lymphocytopenia, hypogammaglobulinemia
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Hypoalbuminemia, hypocalcemia, trace metal deficiency
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Chylous pleural effusions, ascites (Chylous ascites and transudative ascites are reported.)
Complications
Primary intestinal lymphangiectasia is associated with an increased risk of lymphoma.
Fibrotic entrapment of the small bowel is reported in patients with congenital intestinal lymphangiectasia.
Oral manifestations include gingivitis caused by poor lymphocytic function and enamel defects caused by poor calcium absorption.
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Intestinal villi of normal height with dilated lymphatics as usually seen on histology of villi in intestinal lymphagiectasia.