Boykin Spaniel, Male, 4 years 8 months of age

History:

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.

Conclusions:

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.

References:

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”

 

 

2 comments

  1. Hi all, this is an interesting case. Thanks for sharing. I wanted to share my interpretation of these radiographs from a radiology resident’s perspective. =) Please feel free to critique me.

    FINDINGS:
    – In the mid aspect of a segment of small intestine located in the cranial mid abdomen, likely associated with the descending duodenal lumen, there is a large (spanning approximately two lumbar vertebrae), round, well-defined, soft tissue opaque mass, which is surrounded by gas. In the upper GI study, this mass appears as a contrast filling defect, further characterized by a focal widening of the duodenal lumen and abrupt tapering orally and aborally. The positive contrast medium is seen in the stomach and small intestines. The stomach is normal in size and anatomic position. The remainder of the small intestines is diffusely, mildly distended, but otherwise normal in size and uniform in distribution. In the colon, a small amount of granular mineral opaque material is present. Additionally, a small amount of positive contrast medium is seen conforming to the luminal surface of the colon.
    – The peritoneal serosal detail is normal.
    – The remainder of the abdomen is normal.

    CONCLUSION:
    1. Mid duodenal mural mass, likely causing delayed gastric emptying, with concurrent small intestinal functional ileus. My primary differential diagnosis is Pythium insidiosum, however, malignant neoplasia such as adenocarcinoma, lymphoma, or mast cell tumor is not excluded.

    My next step is to take three view thoracic radiographs to rule-out pulmonary metastatic disease as neoplasia is a differential diagnosis. In addition, I would like to take serial abdominal radiographs to monitor the progression of contrast throughout the gastrointestinal tract as the upper GI study is not time-stamped. When the contrast has sufficiently reduced in amount or is completely gone, I would like to do an abdominal ultrasound to further characterize this mass and obtain ultrasound guided samples of this mass for cytology and also to assess the remainder of the abdomen for abdominal lymphadenopathy as well as regional metastatic disease.

  2. The peritoneal serosal margins are well-defined. The liver, spleen, and kidneys are normal in size, shape, opacity, and position. The stomach contains a very mild amount of gas. The small intestines are generally normal in size and diffusely homogeneously soft tissue opaque. The colon contains a moderate amount of formed feces.

    Impression: Unremarkable abdomen with no evidence of the cause of the described vomiting. Potential etiologies to consider include: pyloric outflow tract obstruction (ie. due to a mass or a non-mineral intraluminal foreign body) or fungal gastroenteropathy (ie. histoplasmosis or pythiosis given the history of drinking moldy water). Less likely differentials would include a metabolic disorder (ie. hypoadrenocorticism) or severe food allergies/inflammatory bowel disease with protein losing enteropathy.

    I would recommend more imaging on this case with potential options including a barium gastrointestinal examination to look for altered GI function, an abdominal ultrasound for evaluation of the gastrointestinal wall (ie. assess thickness, wall layer distinction, and/or evidence of a mass), or hydrohelical abdominal CT with IV contrast administration. Clearly the administration of barium or water for these studies may be precluded by the patient’s vomiting.

    Thank you!

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