Chyloabdomen in a cat with pancreatic carcinoma

Véran, Emilie; Gallay-Lepoutre, Julie; Gory, Guillaume; Guillaumot, Pierre; Duboy, Julie

Discussion Chyloabdomen is an uncommon condition in veterinary medicine, with sparse data available in the literature. It results from leakage of triglycerides-rich lymph formed in intestinal lacteals into the peritoneal cavity, due to damage or obstruction of the lymphatic system or one of its tributaries (Al-Busafi et al., 2014) . Unlike chylothorax, which is frequently diagnosed as idiopathic, no idiopathic chyloabdomen has been http://www.openveterinaryjournal.com E. Véran et al. Open Veterinary Journal, (2018) , Vol. 8(4): 452-457 ________________________________________________________________________________________________________ described. The differential diagnosis includes tumor, congestive heart failure, infectious diseases (feline infectious peritonitis, feline immunodeficiency), ruptured cisterna chyli, mesenteric root strangulation or lymphatic vessels malformation. Cases in dogs were reported in association with intestinal lymphangiectasia (Peterson, 1996) , mediastinal lymphangiosarcoma (Myers et al., 1966) , acute pancreatitis (Lott et al., 2015) , abdominal lymphatic rupture (Fossum et al., 1992) , complication of mesenteric lymphangiography for chylothorax (Fossum et al., 1992) , and lymphatic obstruction secondary to thrombus formation (Fossum et al., 1992) . In contrast, chylous ascites in cats have mainly been reported in association with neoplastic disease. In the unique published case series of feline chyloabdomen, seven of 9 cats had intra-abdominal malignancy: 4 were diagnosed with a nonresectable solid tumor (hemangiosarcoma, paraganglioma), 2 with lymphoma of the small intestine infiltrating the mesenteric lymph nodes, and one with lymphangiosarcoma of the abdominal wall (Gores et al., 1994) . The remaining 2 cats had nonneoplastic diseases: biliary cirrhosis, and steatitis caused by vitamin E deficiency (Gores et al., 1994) . Chyloabdomen has also been associated with feline immunodeficiency virus (Börkü et al., 2005) , feline infectious peritonitis (Savary et al., 2001) and hypertrophic cardiomyopathy (Nelson, 2001) . A case of chylous pleural and peritoneal effusion with no underlying cause was described in a cat, with no postmortem examination performed (Thompson and Carr, 2002) . In this case report, pancreatic carcinoma was identified as the underlying cause of the chyloabdomen. Linderman et al. (2013) previously reported 34 feline cases of pancreatic carcinoma; chylous ascites was present in one cat in this series. In human medicine, direct malignant cells invasion into lymphatic vessels and obstruction of lymphatic flow by lymph node metastatic infiltration are thought to explain chyloabdomen formation during neoplastic disease (Al-Busafi et al., 2014) . In this particular case, the mesenteric adipose tissue showed necrotic and granulomatous remodeling on histopathology. This might have led to an obstruction of lymphatic flow and subsequent leakage of chyle. CT lymphangiography is an imaging technique used to assess lymphatic networks through injection of contrast agents. It is frequently used for exploration of chylous effusion when first-line diagnostic procedures have failed to identify the underlying cause of the effusion. Ultrasound-guided percutaneous lymphography by mesenteric or popliteal lymph node injection has been recently described in cats (Kim et al., 2011; Lee et al., 2012) . However, the mobility of the lymph nodes and the volume of contrast agent to administer (1.5mL) can make the p