Hank, a 10-year-old male neutered coonhound, presented for a 10-day history of gastrointestinal signs including vomiting and diarrhea that improved with hospitalization and medical management at an emergency hospital. Radiographs taken the first day of clinical signs were concerning for small intestinal obstruction, however an abdominal ultrasound taken the following day revealed gas and fluid filled small intestine without an apparent foreign body obstruction. Abdominal lymph nodes were noted to be enlarged and were sampled via FNA returning a cytological diagnosis of strongly reactive without evidence of neoplasia. He was discharged after 36 hours of hospitalization and did well at home for the next week as he was transitioned back to normal diet and activity.
The day of presentation to DoveLewis, Hank was acutely nauseated and anorexic and vomited once. He returned to his primary care veterinarian where abdominal radiographs showed marked small intestinal gas distension. CBC and chemistry were notable for a mild hyperproteinemia (9.2 g/dl) and hyperglobulinemia (6.1 g/dl). He was referred to DoveLewis for abdominal ultrasound and surgical exploration if warranted. At presentation, the 36 kg thin-body-condition dog was dull, tachycardic (120 bpm) and hypertensive (160 mmHg) with an estimated 6% dehydration status. His abdomen was described as having mild distension but comfortable upon palpation. Ultrasound examination showed segmental small intestinal fluid distension with scant peritoneal effusion (Figure 1). Mild lymphadenopathy and mild small intestinal wall thickening were noted. No underlying cause of the fluid distension was found. The owners elected to proceed to abdominal exploration given the chronicity of the dog’s clinical signs and persistence of intestinal distension.
Figure 1: Ultrasound image pre-op. Spleen and abdominal effusion seen in mid abdomen. Upper right corner of image consistent with multilobulated lipoma appearance in surgery.
Pre-operative extended database revealed hypokalemia and hypochloridemia (3.19 and 1.08 mmol/L respectively) with a low PCV of 30%. Lactate and renal values were normal. He was started on IV fluids with potassium supplementation and sent to surgery approximately 4 hours after arrival. Midazolam (0.2 mg/kg IV), fentanyl (2.7 mg/kg) and propofol (4mg/kg IV) were used as premedication and induction and the dog was maintained on a fentanyl CRI, crystalloids and Isoflurane. He was intermittently hypotensive which responded well to fluid boluses (5ml/kg) of Norm-R and showed occasional ventricular premature contractions which were not affecting his blood pressure, nor did they progress to ventricular tachycardia.
At surgery a large, multi-lobulated white mass was found arising from the antimesenteric aspect of the jejunum (Figure 2). The base of the mass was narrow (3 cm x 2-3mm) and affected jejunum was normal in color, diameter and wall thickness based on palpation.
Figure 2: Cranial is to the right. Intestinal lipoma arising from jejunum. Distended loop of jejunum (oral to affected segment) seen cranially. No omentum is visible in this image.
The affected loop of jejunum was torsed 180 degrees with the mass at the apex of the loop pulling the intestine into the caudal abdomen. Mesenteric vasculature for the affected loop was congested along the line of the 180 degrees but without concern for long term viability. A gastric lymph was found to be enlarged and cystic (3x4cm).
The mass was resected from the antimesenteric border with a combination of Ligasure vessel fusion and Metzenbaums taking care to avoid any thermal damage to the jejunal wall. When weighed post-surgery, the resected mass weighed 1.4 kg. An orogastric tube was passed to decompress the stomach and the cystic structure suspected to be a lymph node was aspirated using a syringe and 22 g needle, removing 3 ml of amber fluid. Fluid intestinal contents were milked aborally beyond the previous torsion site into the colon.
Hank recovered well from surgery and was discharged the following day on gabapentin (10mg/kg PO q12 hours) and tramadol (4mg/kg PO q8-12hours) and a post-surgical recovery diet plan. The cystic fluid was examined cytologically and interpreted as a reactive lymph node with no evidence of lymphoma or other neoplasia seen. The mass was diagnosed as a lipoma (well differentiated fatty tissue) with no evidence of a neoplastic process. Recovery at home was uneventful with no recurrence of clinical signs 6 months post-procedure.
Abdominal lipomas are an uncommon cause of acute abdomen in companion animals. Frequently the source of a strangulating intestinal lesion in horses, the veterinary literature has limited reports of lipomas originating from the intestine in dogs or cats. More commonly seen are abdominal lipomas within the body wall (inter-muscular) or retroperitoneal lipomas as well as those originating from the omentum in dogs. Large body-wall lipomas can be identified in plain radiographs due to their consistent displacement of abdominal structures combined with a generally uniform radiodensity (usually radiolucent compared to neighboring spleen or liver). Simple accumulation of abdominal adiopose tissue associated with body condition can look similar on plain radiographs. Although Hank’s intestinal lipoma was large (14-16 cm diameter), the multilobular nature and its relative mobility made it difficult to discern in radiographs and ultrasound examination.
The primary concerns for abdominal lipomas include a) transformation into a malignant state (e.g. liposarcoma or infiltrative lipoma), b) progression to a necrotic lipoma and c) displacement and/or strangulation of other abdominal structures. Identifying an abdominal lipoma in a non-symptomatic dog should begin a rational discussion with the clients as to whether surgical intervention is necessary. For the dog of this case report, his recurrent gastrointestinal signs and acute abdominal pain made the decision to go to surgery relatively straightforward in spite of failing to find a discrete reason for his intestinal distension during two specialist ultrasound examinations and multiple radiographs. Perhaps the most intriguing aspect of this dog’s case is the mass’ narrow base originating from the antimesenteric aspect of the jejunum, an area generally devoid of lipomatous tissue. His omentum was unremarkable and not associated with the site at the time of surgery.
DoveLewis would like to thank Hank’s owners for allowing use of his case for teaching purposes as well as Sorrento Animal Hospital for referral.
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