The prevalence of intra‐tumoral and distant thrombi, as well as tumour‐cell emboli in canine neoplasia

Abstract

Macroscopic thromboembolic disease has been associated with canine neoplasia, whereas prevalence studies of concurrent microthrombi and tumour-cell emboli are lacking. This retrospective study investigated microthrombi and tumour cell emboli by reviewing pathology records of dogs diagnosed with lymphoma, sarcoma, carcinoma and mast cell tumours with a concurrent description of thrombi or emboli.

A prospective evaluation of the prevalence of thromboemboli and associated hemostatic dysfunction in dogs with carcinoma or sarcoma

“…The overall prevalence for microthrombi in tumor‐bearing dogs in this study was 50%, of which 68% were exclusively intra‐tumoral, 16% were intra‐tumoral and distant, while 16% were exclusively distant. In contrast, a 2.6% prevalence for microthrombi in biopsies or post mortems of 2274 solid tumors was reported in a recent retrospective study 10 . Of the microthrombi reported, 91% were exclusively intra‐tumoral and 9% distant.…”

“…Macrothrombi were defined as visible and palpable thrombi within macroscopic blood vessels identified during post mortem examination and confirmed on histopathology to be a mesh of cross‐linked fibrin protein with varying amounts of aggregated platelets, white blood cells, and red blood cells 10 . Microthrombi were defined as a mesh of cross‐linked fibrin protein forming a thrombus‐like structure within microscopic blood vessels, adherent to the vessel wall after tissue processing, with varying amounts of aggregated platelets, white blood cells, and red blood cells 10 . Intra‐tumoral thrombi were classified as the thrombi identified within the vasculature of the primary tumor.…”

“…Cancer has also been recognized as one of the most common causes of thrombosis in dogs 7‐9 . The prevalence of thromboembolic disease was reported as low as 2.6% in a retrospective study of dogs with solid tumors 10 …”

“…Microthrombi are aggregates of fibrin, red blood cells, and platelets within blood vessels that remain after tissue processing, 10 are thought to be integral to the development of macrothrombi, cause substantial vascular injury, 21‐23 and play a role in the seeding and survival of metastatic tumor cells 24,25 . Intra‐tumoral microthrombi have previously been described in dogs with various solid tumors 10,26‐28 …”

Corrigendum

“…In the referenced article, Pazzi et al, (2022), 1 the author would like to correct the three mentioned “(*removed for review)” to “the Department of Pathology, Faculty of Veterinary Science, University of Pretoria; Faculty Research Ethics Committee of the University of Pretoria (Number: Rec161‐19) and University of Pretoria's Faculty of Veterinary Science” in the 2.1 Case selection sub‐section of the Materials and Methods section. The corrected text should read as follows:…”