Use of contrast-enhanced ultrasonography for the detection of a feline insulinoma

Abstract

Case summary A 14-year-old cat was presented with a 2-week history of ataxia, seizure-like episodes, vomiting and weight loss. Serum biochemistry revealed severe hypoglycaemia, associated with low serum fructosamine and high insulin concentrations. On abdominal ultrasound, a focal hypoechoic well-defined mass in the left limb of the pancreas was identified and the presence of an additional smaller nodule was suspected. Contrast-enhanced ultrasonography (CEUS) confirmed the presence of both lesions and revealed a third, even smaller nodule. Partial pancreatectomy was performed. Histopathology and immunohistochemistry confirmed the presence of a multifocal insulinoma. Six months later, the cat presented with tenesmus and obstipation. A colorectal adenocarcinoma was diagnosed with histopathology after partial excision of a colorectal mass. The cat was euthanased a month later owing to recurrent episodes of severe obstipation. Relevance and novel information This is the first clinical description of the use of CEUS in the diagnosis of feline insulinoma. Furthermore, the available scientific literature on feline insulinoma was reviewed.

B-Mode and Contrast Enhanced Ultrasonography Features of Gastric Inflammatory and Neoplastic Diseases in Dogs

“…This US technique allows to perform qualitative and quantitative vascular assessment of various organs in both physiological and pathological conditions in dogs and cats [ 3 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ]. Nowadays, CEUS has proven its usefulness in the characterization of inflammatory and neoplastic diseases in veterinary literature [ 26 , 27 , 28 , 29 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ]. Regarding the stomach, a recent study described qualitative and quantitative B-mode and CEUS features of gastric wall in healthy cats, cats affected by gastritis, and cats with low and high grade gastric AL, reporting that gastritis and low grade AL had large overlap of qualitative and quantitative parameters both on B-mode and CEUS, while high grade AL usually appears as a severe hypoechoich wall thickening with absent layer definition, high-contrast uptake, a specific enhancement pattern with “comb teeth-like” vessels (parallel curvilinear structures representing arterial branching within the gastric wall) and associated regional lymphadenopathy, and local steatitis [ 41 ].…”

B-Mode and Contrast Enhanced Ultrasonography Features of Gastric Inflammatory and Neoplastic Diseases in Cats

“…Contrast-enhanced ultrasonography (CEUS) is an imaging modality that could improve the diagnostic accuracy of standard US: the use of intravascular contrast medium (CM), like the second-generation ones, may improve the visualization of blood perfusion and microvascular architecture, allowing qualitative and quantitative vascular assessment of various organs in both physiological and pathological conditions in dogs and cats [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. Furthermore, CEUS has proved to be an extremely safe and well-tolerated technique [ 31 ].…”

“…Furthermore, CEUS has proved to be an extremely safe and well-tolerated technique [ 31 ]. In veterinary medicine, several studies have described the usefulness of this modality in the characterization of inflammatory and neoplastic diseases [ 16 , 18 , 19 , 21 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 32 ]. However, regarding the stomach, only one study has been conducted to investigate the reliability of low-mechanical index imaging compered to Doppler flowmetry for the assessment of gastric mucosal blood flow in healthy dogs, demonstrating the feasibility of CEUS quantitative evaluation in this organ [ 33 ].…”

Feline abdominal ultrasonography: What’s normal? What’s abnormal? The pancreas

“…1,82 These descriptions are further supported by the most recent report of insulinoma, in a 14-year-old male neutered domestic shorthair cat, which describes the presence of a focal, well-defined hypoechoic pancreatic mass measuring 16 mm x 23 mm diameter. 83…”

“…Contrast-enhanced ultrasonography has also been used in the diagnosis of pancreatic insulinoma in a cat. 83 Further research is required to determine whether this technique can be used in cats that are suspected of having pancreatic pathology but have normal B-mode scans, and to determine the accuracy of Doppler with regard to differentiating the various disorders of the pancreas.…”