In veterinary medicine, contrast-enhanced ultrasonography allowed the accurate quantification of liver, splenic and kidney vascularization in healthy dogs and the differentiation between malignant and benign hepatic, renal, and splenic nodules in dogs and cats based on perfusion patterns. The utility of contrast-enhanced ultrasonography in other applications is still under study. The aim of this study was to develop diagnostic criteria by contrast-enhanced ultrasonography in 8 client-owned adult dogs affected by urinary bladder transitional cell carcinoma with definitive diagnosis made by cytopathologic evaluation after suction biopsy. The contrast enhancement pattern and the quantification of blood flow parameters of this tumor were reported. Examinations with B-mode, Doppler ultrasonography and contrast-enhanced ultrasonography were performed in all not sedated dogs. Assessments of bladder masses and bladder wall infiltration were performed. Each dog received 2 bolus injections of sulfur hexafluoride during the contrast-enhanced ultrasonography. Quantitative analysis of the contrast-enhanced ultrasonography images were performed. For each dog, one region of interest was manually drawn around the entire tumor. Software analysis of contrast-enhanced time-intensity curves was used to identify peak enhancement, time to peak enhancement, regional blood volume, regional blood flow, and mean transit time. Contrast-enhanced ultrasonography showed an avid enhancement of the tumour tissue, with a heterogeneous or homogeneous pattern. The exam also showed the loss of planes between the lesion and the muscular layer. The presence of vascularized tissue through the bladder wall confirms the infiltrative feature of the tumour. Post-processing quantitative analysis showed a time-intensity curve with a rapid wash-in, a low level of signal intensity and a slow wash-out. Contrast-enhanced ultrasonography provided useful clinical information and defined a vascular enhancement patterns and calculated parameters associated with TCC. It may be a useful, noninvasive and reproducible tool for detecting these tumors in dogs.

Neoplastic progression is influenced by the expression of tumour antigens that activate an anti-tumour immune response. Human medical studies show that this body defence is carried out in secondary lymphoid organs (SLOs) but also directly in the tumour through organized cellular aggregates that are called tertiary lymphoid structures (TLSs). However, their occurrence has different meanings in different tumour types. For example, the presence of TLSs in breast cancer is associated with the most aggressive subtypes. This paper aimed to study TLSs in canine mammary simple carcinomas. A morphological assessment of the inflammatory infiltrate was performed on H&E sections of fifty cases. Immunohistochemistry was then carried out to typify the inflammatory cells in the tumour microenvironment. Results showed that, sometimes, inflammatory infiltrates were organized in follicles close to high-grade carcinomas, simulating a lymphoid organization, as in breast cancer. Therefore, we can assume that even in canine mammary tumours, TLSs exist and they are entities to consider due to their presence in the most aggressive histotypes or tumours with a high degree of malignancy.