Chylous ascites (also known as chyloperitoneum) is defined as the abnormal intraperitoneal accumulation of milky lymphatic fluid with a triglyceride level >110 mg/dL 1. Aetiologically it is due to a disruption of the lymphatic system, most commonly obstructive due to a mass or traumatic (which maybe iatrogenic).
On this page:
Clinical presentation
abdominal distension
abdominal discomfort
dyspnoea: splinting of the diaphragm by ascites
sequelae of hypoproteinaemia: oedema
acute abdomen: acute chylous peritonitis 2
For fluid aspirated from the abdomen to be chyle, triglycerides need to be elevated above 110 mg/dL (two to eightfold more than normal plasma concentration) with a specific gravity >1.012.
Pathology
Aetiology
The pathogenesis of chylous ascites relies upon a disruption to the normal lymphatic pathways 1,2:
obstruction of the lymphatics: usually a mass e.g. malignancy
fistula between the lymphatics and the peritoneum/mesentery: usually trauma or surgery
leakage of retroperitoneal megalymphatics: usually congenital
Radiographic features
Large volume fluid in the peritoneal cavity is the normal finding. However, if the patient is allowed to remain supine for a short interval then the fat commonly rises to the top of the fluid (fat is less dense than water), producing a fat-fluid level (cf. chyluria), which is highly specific for chyloperitoneum.
CT
On CT, chylous ascites is indistinguishable from water on density measurements. Fat-fluid levels are common.
MRI
On MRI, due to its high fat content, chylous ascites often demonstrates distinctive signal drop out on fat saturated sequences.
History and etymology
Morton described a case of a boy dying from chylous ascites caused by tuberculosis in 1694, the first known appearance of this condition in the literature 2.
Unable to process the form. Check for errors and try again.