60


EQUINE VETERINARY EDUCATION


Equine vet. Educ. (2018) 30 (2) 60-63 doi: 10.1111/eve.12606


Case Report Ultrasonographic features of pedunculated lipomas in two horses G. Manso-Dıaz†*,F.J. L


opez-Sanrom aceres, Spain. an†, J. Jim


*Corresponding author email: gmanso@ucm.es Keywords: horse; abdomen; colic; small intestine; strangulation


Summary Small intestine strangulation by pedunculated lipomas is a common cause of acute colic in horses. However, diagnosis of this condition prior to surgery may be difficult due to the poor specificity of the clinical signs. We describe the ultrasonographic findings of 2 horses presented for acute colic with a diagnosis of strangulating lipoma confirmed in surgery. Lipomas were identified as rounded and well- defined, homogeneous hyperechoic structures, surrounded by distended small intestine loops and peritoneal fluid. Ultrasonographic identification of lipomas should be attempted during an abdominal scan, especially in horses with evidence of small intestinal ileus and/or obstruction.


Introduction


Lipomas are benign hyperplastic growths of well- differentiated adipocytes. Abdominal lipomas originate from mesenteric adipose tissue and can be solitary or multiple, broad-based or pedunculated (Blikslager et al. 1992; Mair and Edwards 2003; Garcıa-Seco et al. 2005). Although most lipomas originate from the small intestine mesentery, lipomas associated with the mesentery of the descending colon, rectum and caecum have also been described (Mason 1978; Blikslager et al. 1992; Dart et al. 1992; Edwards and Proudman 1994; Prange et al. 2010). Lipomas may be incidental intraoperative findings; however, these masses can cause a strangulating or nonstrangulating obstruction when they wrap around the intestine and mesentery (Edwards and Proudman 1994; Freeman and Schaeffer 2001). Strangulation by pedunculated lipomas is one of the most common causes of strangulating obstruction of the small intestine in horses, with castrated male Saddlebred and Arabian geldings older than 14 years being overrepresented (Garcıa-Seco et al. 2005). Outside of the abdomen, lipomas have been described histopathologically in the myocardium, pericardium, meninges and musculoskeletal system (Bristol and Fubini 1984; Baker and Kreeger 1987; Anderson and King 1988; Hamir et al. 1994; Hammer et al. 2002; Rebsamen et al. 2010; Owens et al. 2017). In addition, ultrasonographic description of lipomas of tendon sheaths are available in the literature, consisting of well-defined heterogeneous and echogenic masses (Hammer et al. 2002; Owens et al. 2017). Conversely, infiltrating lipomas of the lumbar musculature present poorly defined borders on ultrasound examination (Rebsamen et al. 2010). To the author’s knowledge this is the first description of the ultrasonographic appearance of confirmed mesenteric pedunculated lipomas in horses.


© 2016 EVJ Ltd Case descriptions


Case 1 History and clinical findings A 16-year-old, 480 kg Arabian mare was evaluated because of acute signs of abdominal pain that had lasted for 2 h. The


referring veterinarian administered xylazine, butorphanol and flunixin meglumine prior to the referral. On clinical assessment, heart rate was 48 beats/min,


respiratory rate was 16 breaths/min, temperature was 37.3°C and capillary refill time was <2 s. The mucous membranes were cyanotic. Borborygmi were decreased on both sides. No reflux was present on nasogastric intubation, and on rectal examination distended small intestinal loops were noted. The haematology values were within the physiological limits. Biochemical abnormalities included slight hypocalcaemia (9.76 mg/dL), an hyperlactataemia (3 mmol/ L) and hyperfibrinogenaemia (0.6 g/dL). The rest of the biochemical profile was normal. The peritoneal fluid analysis revealed high lactate concentration (4 mmol/L), increased protein concentration (2.3 g/dL) and high leucocyte count (9.3 9 109/L).


Abdominal ultrasonography Abdominal ultrasonography was performed transcutaneously using a 5.0 MHz curvilinear array transducer (MyLab301), showing distended loops of small intestine in the ventral and caudal portion of the abdomen. The diameter of the distended loops of small intestine was >6 cm and no appreciable increase in thickness of the walls was observed. A moderate amount of anechoic peritoneal fluid was present in the cranial and ventral abdominal cavity. A rounded and well-defined mass was also identified in the caudoventral aspect of the right side of the abdomen, measuring approximately 16 9 17 cm (Fig 1a). The mass had an overall hyperechoic appearance, showing a focal heterogeneous


hypoechoic area. On the basis of the ultrasonographic findings a diagnosis of small intestine strangulation secondary to a possible pedunculated lipoma was established.


Treatment and outcome An exploratory laparotomy under general anaesthesia was performed. A 20 cm diameter, yellowish and smooth with a bright surface pedunculated lipoma was identified in the ventral and caudal part of the abdomen. The pedicle was 10 cm long and it was wrapped around the small intestine (middle of the jejunum) causing ischaemic necrosis of about 60 cm in the middle jejunum. The appearance of the bowel did not improve after reduction and decompression and


enez‡, L. J. Ezquerra‡ and M. Martın-Cuervo‡


†Department of Animal Medicine and Surgery, School of Veterinary Medicine, Universidad Complutense de Madrid, Madrid; and ‡Department of Animal Medicine, School of Veterinary Medicine, Universidad de Extremadura, C


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