Ultrasonographic features of intestinal lipogranulomatous lymphangitis in 10 dogs

Intestinal lipogranulomatous lymphangitis (ILL) is a granulomatous inflammation of the lymphatic vessels of the intestinal wall and mesentery characterized by lipogranulomas. The purpose of this retrospective, multi-center, case series study is to report the ultrasonographic features of canine ILL. Ten dogs with a histologically confirmed ILL undergoing preoperative abdominal ultrasound were retrospectively included. Additional CT was available in two cases. Lesion distribution was focal in eight dogs and multifocal in two. All dogs presented with intestinal wall thickening and two had a concomitant mesenteric mass adjacent to the intestinal lesion. All lesions were in the small intestine. Ultrasonographic features were altered wall layering with predominantly muscular and to a lesser extent submucosal layer thickening. Other findings included hyperechoic nodular tissue within the muscular, serosa/subserosal, and mucosal layers, hyperechoic perilesional mesentery, enlarged submucosal blood/lymphatic vessels, mild peritoneal effusion, intestinal corrugation, and mild lymphadenomegaly. The two intestinal to mesenteric masses presented heterogeneous echostructure, predominantly hyperechoic with multiple hypo/anechoic cavitations filled with mixed fluid and fat attenuation content on CT. Histopathological findings included lymphangiectasia, granulomatous inflammation, and structured lipogranulomas affecting mainly submucosa, muscularis, and serosa. The intestinal to mesenteric cavitary masses revealed severe granulomatous peritonitis with steatonecrosis. In conclusion, ILL should be considered as a differential diagnosis for dogs with this combination of ultrasonographic features.