Primary intestinal lymphangiectasia (PIL), also known as Waldmann's disease, is 
an exudative enteropathy resulting from morphologic abnormalities in the 
intestinal lymphatics. In this article, we describe a 12-year-old boy with PIL 
that led to protein-losing enteropathy characterized by diarrhea, 
hypoalbuminemia associated with edema (serum albumin level: 1.0 g/dL), and 
hypogammaglobulinemia (serum IgG level: 144 mg/dL). Severe hypoalbuminemia, 
electrolyte abnormalities, and tetany persisted despite a low-fat diet and 
propranolol. Everolimus (1.6 mg/m(2)/day) was added to his treatment as an 
antiangiogenic agent. With everolimus treatment, the patient's diarrhea resolved 
and replacement therapy for hypoproteinemia was less frequent. Hematologic and 
scintigraphy findings also improved (serum albumin level: 2.5 g/dL). There were 
no adverse reactions during the 12-month follow-up. To the best of our 
knowledge, this is the first report of everolimus use in a patient with PIL.