Contrast-enhanced computed tomography findings of canine primary renal tumors including renal cell carcinoma, lymphoma, and hemangiosarcoma

Abstract

In veterinary medicine, abdominal ultrasonography is used to rank the differential diagnosis of renal lesions. However, a conventional sonographic examination may show nonspecific findings. The purpose of this study was to assess the computed tomography (CT) findings of canine renal tumors, including renal cell carcinoma (RCC), lymphoma, and hemangiosarcoma (HSA). In this retrospective study, the following CT parameters were recorded for each dog: 1) extent of renal involvement of tumors, 2) enhancement pattern, 3) number of renal tumors, 4) renal tumor vessel enhancement in the corticomedullary phase, 5) presence of lymphadenopathy and lung metastasis, and 6) attenuation values of the renal tumors on the pre- and post-contrast corticomedullary, nephrographic, and excretory phase images. Fifteen dogs met the inclusion criteria, of which nine had RCCs, four had lymphomas, and two had HSAs. RCCs tended to show heterogeneous enhancement and unilateral renal involvement, and vessel enhancement was detected in the corticomedullary phase in dogs with RCC. Conversely, renal lymphomas showed homogeneous enhancement, bilateral renal involvement, and multiple masses; in these dogs, no vessel enhancement was detected in the corticomedullary phase, and the incidence of lymphadenopathy was low. However, in dogs with lymphadenopathy, the renal lymphoma was associated with regionally severe lymphadenopathy. Finally, renal HSAs tended to show heterogeneous enhancement with a non-enhanced area and unilateral renal involvement; in these dogs, vessel enhancement was detected in the nephrographic phase, with the enhancement expanding around the vessel. These findings had no significant differences. Further studies with a larger sample size are required to examine the association between CT and histopathological findings.

Imaging features of unilateral renal T‐cell lymphoma occurring simultaneously in the urinary bladder wall and contralateral ureter with secondary polycythaemia in a dog

“…12 Although no significant differences were found between CT and histopathological findings and further studies are needed, renal lymphoma showed homogeneous enhancement, bilateral involvement and multiples masses, while renal cell carcinoma and hemangiosarcomas tended to show heterogeneous enhancement and unilateral renal involvement. 12 In our case, the CT study revealed a large, irregular soft tissue expansile mass within the cranial pole of the right kidney with homogeneous enhancement, hypodense compared with the adjacent normal renal tissue, in agreement with previous studies in humans and dogs. 8,12 In humans this finding is attributed to the fact that the lymphomatous tissue enhances less than the normal renal parenchyma, which helps to differentiate it from squamous cell carcinoma, which usually enhances in the arterial phase.…”

“…Multi‐phase contrast‐enhanced CT is used in dogs to assess pathologies affecting the kidney 18 while in humans, in addition to CT, MRI is also used for the evaluation of renal tumours in order to reduce the incidence of complications that may appear after a renal biopsy 19 . In a recent retrospective study, the tomographic findings of different canine kidney tumours were evaluated 12 . Although no significant differences were found between CT and histopathological findings and further studies are needed, renal lymphoma showed homogeneous enhancement, bilateral involvement and multiples masses, while renal cell carcinoma and hemangiosarcomas tended to show heterogeneous enhancement and unilateral renal involvement 12 .…”

“…Alternative differential diagnosis for the renal mass included tumours of epithelial origin: carcinoma, adenocarcinoma and transitional cell carcinoma, and non-epithelial neoplasms: hemangiosarcoma, fibrosarcoma and anaplastic sarcoma among others. 11,12 Differentials for the ureter mass were transitional cell carcinoma, leiomyoma and leiomyosarcoma, mast cell tumour, spindle cell sarcoma and other sarcomas. 13 And for the bladder mass, differential diagnosis included tumours of epithelial origin like the transitional cell carcinoma, followed by squamous cell carcinoma, adenocarcinoma and undifferentiated carcinoma; as non-epithelial origin tumours would be considered: leiomyomas and leiomyosarcomas, haemangiomas and haemangiosarcomas, fibromas and fibrosarcomas.…”

“…On the basis of the imaging findings, clinical pathology, clonality and immunocytochemistry, the most likely diagnosis was a right renal lymphoma, simultaneously involving the contralateral ureter and the wall of the urinary bladder. Alternative differential diagnosis for the renal mass included tumours of epithelial origin: carcinoma, adenocarcinoma and transitional cell carcinoma, and non‐epithelial neoplasms: hemangiosarcoma, fibrosarcoma and anaplastic sarcoma among others 11, 12 . Differentials for the ureter mass were transitional cell carcinoma, leiomyoma and leiomyosarcoma, mast cell tumour, spindle cell sarcoma and other sarcomas 13 .…”

Diagnostic features of canine lymphoma (a review)

“…Вважають, що значне збільшення розмірів лімфатичних вузлів, їх округлості, Solbiati-індексу (SI), співвідношення між короткою віссю і довжиною лімфатичного вузла (S/L) та гіпоехогенні зміни в лімфатичних вузлах у собак із злоякісною лімфомою стають показовими параметрами злоякісності. Дослідники подають ультрасонографічні характеристики ниркової лімфоми собак, критерії диференціювання пухлинних і непухлинних уражень (Taylor et al, 2014;McAloney et al, 2018;Tanaka et al, 2019). Останнім часом у медичній і ветеринарній онкології дискутується можливість заміни біопсії сучасними методами діагностичної візуалізації: ультразвукове дослідження з контрастним підсиленням; комп'ютерна томографія; позитронно-емісійна томографія; магнітнорезонансна томографія (Škor, 2019).…”