Primary Intestinal Lymphangiectasia Isolated to the Colon: A Rare Cause of Chylous Ascites

Abstract

Purpose: Recognize primary intestinal lymphangiectasia as a rare cause of chylous ascites. Case: A 20-year-old male with twp years of watery diarrhea and protein-losing enteropathy of uncertain etiology presented to our hospital with abdominal distention and pain. He denied trauma, travel, abdominal surgery, alcohol use, or family history of gastrointesintal disorders. Prior work-up including esophagogastroduodenoscopy (EGD), colonoscopy, capsule endoscopy, stool studies, and HIV test was unremarkable, except for an elevated fecal alpha-1-antitrypsin level. Physical exam was notable for a tensely distended, non-tender abdomen without hepatosplenomegaly, lymphadenopathy, or edema. Labs revealed hypoalbuminemia, hypoprotienemia, lymphopenia, and low IgG. Paracentesis yielded 5 L of milky white fluid with triglycerides of 1656 mg/dL, consistent with chylous ascites. Fluid culture and cytology were negative. CT abdomen showed extensive lymphadenopathy, but image-guided biopsy was not possible due to the small size of the lymph nodes. CT chest and neck, PET/CT, echocardiogram, PPD, LDH, germ cell tumor markers, and urine 5-HIAA were unremarkable. Lymphoscintigraphy revealed abdominal chylous leak of unknown origin without evidence of obstruction. Exploratory laparoscopy confirmed innumerable peritoneal lymphangiectasias between 5 mm and 2 cm limited to the distal transverse, descending, sigmoid colon, and proximal rectum. Intraoperative Argon beam coagulation was unsuccessful at reducing lymphangitic leakage. Despite a high protein, low-fat diet, the patient continues to require weekly paracentesis. Discussion: Primary intestinal lymphangiectasia (PIL) is a rare congenital malformation of the intestinal lymphatic system, characterized by protein losing enteropathy, hypoproteinemia, lymphopenia, and hypogammoglobulinemia. Lesions typically affect the small bowel and present at an early age with symptoms such as lower extremity edema, chronic diarrhea, steatorrhea, chylous ascites, and lymphedema. EGD or capsule endoscopy may show a characteristic appearance of edematous small bowel mucosa with engorged white villi. Lymphangiography may be a useful diagnostic study when endoscopic visualization and biopsy fail to confirm a diagnosis. The mainstay of treatment remains dietary reduction of long-chain triglycerides (LCT) and a high-protein diet. Several features about this case of PIL are unique, including lesions isolated to the left side of the colon, sparing the small bowel and the relatively late age of symptom onset. Given the isolated colonic involvement, it is perhaps not surprising that dietary elimination of LCT did not improve this patient's symptoms, but may make a left hemicolectomy a future treatment option.