Pronóstico de mastocitomas cutáneos caninos mediante la correlación entre características histopatológicas y la expresión de ki67 en clínicas veterinarias del cantón Huaquillas, El Oro, Ecuador.

Abstract

Canine cutaneous mast cell tumors (CMT) are one of the most common neoplasms in dogs, with highly variable clinical behavior that makes establishing a precise prognosis difficult. This study aimed to determine the relationship between histopathological characteristics and Ki-67 marker expression in cutaneous mast cell tumors from dogs treated at veterinary clinics in Huaquillas canton, El Oro province, Ecuador, in order to provide prognostic criteria applicable in clinical settings with limited resources. Ten cases were analyzed using histopathological and immunohistochemical techniques, employing the Kiupel classification and quantification of the Ki-67 index. Hematoxylin-eosin staining classified 50% of the tumors as high-grade and the other 50% as low-grade, while Giemsa staining identified 60% as high-grade. All cases showed Ki-67 expression below 10.6%, with a mean of 1.97%, indicating low proliferative activity and suggesting a biologically favorable prognosis. No statistically significant correlation was found between histological grade and the Ki-67 index, nor with clinical variables such as sex, breed, age, or anatomical location of the tumor, although some interesting trends were observed that warrant further study. These findings highlight the usefulness of Ki-67 as a complementary diagnostic tool, especially in the evaluation of malignant tumors. Furthermore, they promote its incorporation into veterinary clinical practice, especially in regions with limited access to advanced diagnostic methods, thus improving diagnostic accuracy and timely treatment.