Poor appetite and lethargy. Onset of clinical signs corresponded to a bird hunting outing where he drank from a pail of moldy/dirty water. Since then, he has periodic vomiting 10 to 15 mins after eating and his appetite is getting progressively worse. He seems lethargic after eating. Diarrhea has occurred. There is progressive hypoalbuminemia.
Survey radiographs of the abdomen were acquired.
Survey Radiographic Findings:
In the lateral view there is a poorly defined mass effect immediately caudal to the stomach. This appears to be located just to the right of L1 in the VD view. The site of origin of this mass cannot be determined from the survey radiographs. Possibilities include small intestine, pancreas, mesentery and lymph node. There are no other abnormalities. There is no evidence of gastrointestinal dilation or organomegaly, or abdominal fluid.
For further evaluation, a screening ultrasound examination could be performed. However, in general practice a positive contrast gastrointestinal study can often provide valuable information. In this patient, 100 ml. of water soluble contrast medium was diluted 1:1 with water and administered.
Contrast Study Findings:
Contrast medium is present in the stomach, small intestine, cecum and proximal portion of the large intestine. Best seen in the VD view, there is a large soft tissue mass to the right of L1 that is causing a left-lateralized filling defect in the descending duodenum. This indicates the mass is of mural origin, located on the mesenteric border of the duodenum. The mucosal margin of the mass is smooth. The remainder of the gastrointestinal tract is normal. There is no evidence of dilation, other mucosal lesions, or foreign material.
Given the young age of the patient, granulomatous disease is a primary consideration. A neoplastic lesion or a foreign body embedded into the duodenal wall are additional differentials.
For gastrointestinal contrast studies, remember to assess the following: luminal diameter, wall thickening, mucosal pattern, filling defects, transit time, and leakage of contrast medium. If an abnormality is noted, look for its persistence in multiple images and/or at multiple times points and take care to describe location and approximate length of gastrointestinal tract affected.
Additionally, it is helpful to the practice to mention whether you think the study was performed optimally. For a gastrointestinal contrast study, these factors include whether the patient was fasted, whether an appropriate volume of contrast medium was used, whether images were acquired at appropriate time points and labeled correctly, and whether the study was continued until a diagnosis was obtained or until the contrast medium reached the colon.
Abdominal sonography was subsequently performed. There was dilation of the descending duodenum with liquid content. The dilation measured approximately 3 cm and extended over an approximate 8 cm length of duodenum. There was no evidence of shadowing intraluminal ingesta. The duodenal wall at this level measured up to 0.9 cm in thickness with loss of normal wall layering.
Gastroduodenoscopy was performed and there was a large, proliferative, pink, fleshy, frond-like mass obscuring the lumen of the descending duodenum. Multiple endoscopic biopsies were obtained. The histologic diagnosis was adenomatous hyperplasia (polyp) with severe regionally extensive neutrophilic histiocytic enteritis. The patient had a duodenal resection and anastomosis. The final histopathologic diagnosis was papillary cystadenocarcinoma.
BSAVA Manual of Canine and Feline Abdominal Imaging.
Wallack, Seth. The Handbook of Veterinary Contrast Radiography.
Riedesel, E. Thrall Textbook of Veterinary Diagnostic Radiology 6th Edition. “Chapter 44: The Small Bowel”