Primary Intestinal Lymphangiectasia Presenting as Recurrent Chylous Ascites: A Rare Case.

Primary intestinal lymphangiectasia (PIL) is a rare protein-losing enteropathy, typically diagnosed in childhood. Adult-onset PIL is exceptionally rare and poses a significant diagnostic challenge, often diagnosed as other gastrointestinal diseases. A 28-year-old female, presented with recurrent chylous ascites, and hypoalbuminemia (2.3 g/dL); no hepatic dysfunction or immunoglobulin deficiency was evident; comprehensive evaluation excluded hepatic, malignant (lymphoma), and infectious etiologies (tuberculosis, filariasis). Past history is significant for a presumptive diagnosis of Crohn's disease, which was initially made based on clinical picture and laboratory finding of elevated fecal calprotectin, however, endoscopy and histology studies were inconclusive. On further investigations, imaging showed colonic wall thickening with mesenteric lymphadenopathy, and ascitic fluid analysis showed chylous ascites without evidence for malignant or infectious etiology. Upper endoscopy revealed multiple white duodenal plaques, and terminal ileal biopsies confirmed notable lymphatic dilation. Treatment was initiated with dietary modification (low-fat, high-protein, medium-chain triglyceride supplementation) and budesonide; the patient showed partial response. Later on, Octreotide therapy was initiated, and led to gradual resolution of ascites. Adult onset PIL is challenging to diagnose, particularly when initially misdiagnosed as an inflammatory bowel disease. For correct diagnosis, thorough evaluation, by histopathology and exclusion of secondary causes, is essential. Dietary therapy is the mainstay of management; additional benefits can be obtained by pharmacologic options like octreotide in refractory cases. This case is among the first reported cases of adult-onset PIL from Palestine, contributing to the limited literature and highlighting the need for heightened clinical awareness of such rare presentations.