Frecuency of canine round cell tumors diagnosed by cytopathology: Retrospective study in Northeast Mexico (2020-2024)

Abstract

Canine Round Cell Tumors (RCTs) are a group of heterogeneous tumors that originate from hematopoietic cells (mast cell tumor, lymphoma, plasmacytoma and histiocytoma), except for transmissible venereal tumor and melanoma. Diagnosing as early as possible is vital since their biological behavior differs drastically. Although there is research on its prevalence in different countries, including Mexico, it is important to conduct local epidemiological studies, as it has been reported that results might vary depending on the population and geographical area evaluated. Therefore, the objective of this study was to describe the distribution and some epidemiological characteristics of RCTs between 2020 and 2024 at the Department of Pathology, Faculty of Veterinary Medicine and Zootechnia, Autonomous University of Tamaulipas, and two private laboratories. Of the 1,325 evaluated tumors, 411 were diagnosed with RCTs (31 \%). Of these, 167 corresponded to mast cell tumor (40.6 \%), 118 to TVT (28.7 \%), 59 to lymphoma (14.4 \%), 59 to melanoma (14.4 \%), and 8 to histiocytoma (1.9 \%). Female and male were affected similarly in most neoplasms (p = 0.412). According to age, the highest tumor frequency was found at 6 to 10 years (42.1 \%) (p < 0.001). Mixed-breed dogs were the most affected (27.98 \%) (p < 0.001). Mast cell tumor occurred most frequently in different anatomical sites (p < 0.001).