15-year-old spayed female Miniature Poodle

• Successful candidates identified marked fluid distension of the stomach with normal wall layering and thickness in the fundus and body (Figs. 1,2 below).
• Stomach motility was identified during the video clip provided for interpretation.
• An irregular, smoothly marginated, soft tissue mass is observed in the pylorus with maintenance of the wall layering.  The thickening is mainly in the mucosal layer (Fig. 3).
• The proximal duodenum was identified and noted to be non-distended and normal in wall layering and thickness (Fig. 3).
• The peritoneum and small section of the pancreas within the field of view was identified and described as normal.

Correct conclusion is pyloric outflow obstruction caused by a pyloric “mass.”  A benign process should be ranked as the first differential with pyloric mucosal hypertrophy most likely.  Neoplasia was accepted as a second differential but is not thought likely given the maintenance of wall layering in the lesion.  The lesion is not in the muscularis layer or serosa to suggest pyloric muscular hypertrophy or fibrous stricture and should not be in the differential list.  Candidates that listed multiple differentials for the mass in an effort to cover every conceivable possibility including many that are clearly not indicated received lower scores.

No points were given for case management in this case, as the recommendation would typically be surgery.