2005 Radiology Exam - Abdomen Case 1

Objective of the Case
To recognize the presence of gastric wall thickening and mucosal surface irregularity. To provide a reasonable prioritized differential diagnosis for this finding.

Information Provided to Candidate
Seven-year-old spayed female domestic short hair cat. Progressive vomiting of four weeks duration. Depression and mild dehydration. Initial survey radiographs were provided; an additional imaging study was provided (gastrogram) if the candidate recommended additional imaging studies such as an ultrasound, gastrogram or UGI.

See images below. Click to enlarge.

Findings Expected from Candidate
Recognition of a prominent gastric silhouette and irregular gastric mucosal contour in an apparently empty stomach on the initial radiographic examination. There is also a small volume of opaque material in the rectum (barium) that the candidate was instructed to ignore when presented with the initial set of radiographs. Following complete interpretation of the survey study, the candidate should have provided a short differential diagnosis (see below) based on the available radiographic findings then recommended additional imaging studies such as ultrasound or gastrogram to confirm and further characterize these findings. The candidate should have confirmed the presence of pronounced non-uniform gastric wall thickening on the subsequent negative contrast gastrogram.

Conclusions Expected from the Candidate
The differential diagnosis for the initial radiographic study should have included mural causes such neoplasia and inflammatory disease as well as a possible intraluminal abnormality (foreign body). The more clearly defined mural abnormalities seen on the second set of radiographs should have prompted a refinement of the differential to include infiltrative neoplasia such as lymphoma or mast cell tumor, gastric adenocarcinoma and infiltrative inflammatory disease.

Diagnosis: Gastric Lymphoma

Summary of Overall Candidate Performance
Most candidates recognized the salient radiographic findings on the initial study and provided a reasonable differential diagnosis following evaluation of the second examination. Most candidates also made appropriate recommendations for additional imaging studies which included ultrasound or gastrogram/upper GI exam. Candidates were not expected to specifically ask for a negative contrast gastrogram.