Ultrasonographic features of feline gastrointestinal eosinophilic sclerosing fibroplasia on initial presentation and during follow‐up

The aim of this study is to describe the ultrasonographic features of feline gastrointestinal eosinophilic sclerosing fibroplasia (FGESF) before histological diagnosis and during follow-up after surgical excision and/or medical treatment. This multicentric retrospective case series study includes medical records of cats diagnosed histologically, which had an ultrasound before diagnosis and a minimum of one follow-up ultrasound at least 4 weeks after treatment. Thirty cats were included in the study. The average age was 4.9 years (IQR 3.3-9.3 years). In 25 cases, the mass affected the gastrointestinal system, most commonly the proximal duodenum (36%: 9/25). Three masses originated from the lymph nodes, and two were mesenteric. The most common clinical signs were chronic vomiting, weight loss, and anorexia/reduced appetite. In 25 of 30 (83%) FGESF gastrointestinal cases, ultrasonographically, the lesions generally presented as focal, circumferential, eccentric masses with loss of layering, heterogeneous echogenicity, and hyperechoic areas. Hyperechogenicities in the peritoneum were observed in 63% of the cases, and enlarged lymph nodes (88%) were common. On final follow-up, 55% of the patients had complete resolution of the main lesion, peritoneal changes, and lymphadenopathies ultrasonographically. The disease recurred in 11 of 30 (37%), and progression was reported in 10 of 30 (33%) cases during the follow-up. Initially, 9 of these 10 were diagnosed via nonexcisional biopsy (endoscopic biopsy, Trucut biopsy, surgical incisional biopsy) and treated medically; only one patient had had surgical resection of the mass. Clinical signs at the time of recurrence or progression were inconsistent. Feline gastrointestinal eosinophilic sclerosing fibroplasia shows ultrasonographic features similar to neoplasia but commonly demonstrates hyperechoic areas. Data were assessed for normality and then assessed with appropriate parametric or nonparametric tests accordingly. Progression of the disease at any time during the follow-up was more common in cats treated medically than those treated surgically (P = .02). Clinical signs may or may not be present at the time of ultrasonographic recurrence or progression.