IMAGING DIAGNOSIS-RADIOGRAPHIC, ULTRASONOGRAPHIC, AND COMPUTED TOMOGRAPHIC CHARACTERISTICS OF A DUODENAL DUPLICATION CYST IN A YOUNG CAT.

A 7-month-old, 2.8 kg, intact female Siamese cat was evaluated for repetitive and intermittent episodes of vomiting and anorexia. Abdominal palpation revealed a round, firm, nonpainful mass in the right cranial abdomen. Ultrasonography findings were consistent with a cystic structure adjacent to the descending duodenum. The structure exhibited a "muscular rim sign." A duodenal duplication cyst was confirmed by histopathological analysis. Computed tomography ruled out concurrent vertebral anomalies and clarified anatomic relationships for surgical planning. To the authors' knowledge, this is the first description of an ultrasound "muscular rim sign" in a duodenal duplication cyst in a cat.