Computed Tomographic and Ultrasonographic Features of Feline Gastrointestinal Eosinophilic Sclerosing Fibroplasia in Cats.

This study aimed to characterize the computed tomographic (CT) and ultrasonographic features of feline gastrointestinal eosinophilic sclerosing fibroplasia (FGESF) and its concurrent abnormalities. A retrospective multicenter study was conducted on 16 cats with histopathologically confirmed FGESF. CT and ultrasonographic characteristics were retrospectively evaluated to assess the lesion location, shape, size, and layering patterns. The contrast enhancement patterns, including the attenuation values, were analyzed qualitatively and quantitatively. Concurrent abnormalities, such as lymphadenopathy, gastrointestinal (GI) obstruction, and perforation, were also assessed. FGESF predominantly affected young to middle-aged cats (median age: 3.5 years; range: 9 months-9 years), and Ragdolls were the most overrepresented breed among purebred cats. GI involvement was observed in 14 of 16 cases, most commonly in the proximal duodenum (33%). Lesion growth patterns were significantly associated with anatomical location; all proximal duodenal and pyloric lesions demonstrated endophytic growth (p = 0.018). Common CT findings included heterogeneous contrast enhancement (86%), mucosal layer enhancement (86%), and ulceration (50%). Ultrasonography revealed intraparenchymal hyperechoic areas (100%), heterogeneous echotexture (93%), and mixed echogenicity (93%). Concurrent abdominal lymphadenopathy was present in 93% of cases, with 85% showing marked enlargement (>10 mm). GI obstruction (21%) and perforation (14%) were less common; however, perforation cases exhibited poor prognosis, and none of the affected cats survived beyond 24 h postoperatively. These findings support the inclusion of FGESF in the differential diagnosis of GI mass-forming conditions in cats and highlight the utility of CT and ultrasonography for the comprehensive assessment of primary lesions and concurrent abnormalities.