Pathological Diagnosis And Epidemiological Analysis Of Canine Mammary Tumors

With the development of economy and the improvement of living standards,pet welfare and health have become more and more important,pets’ quality of life and longevity have improved,but diseases are also on the rise.Among,neoplastic diseases gradually become an important factor endangering the life and health of pets.As the most common neoplastic disease in female dogs,mammary tumors should be paid to the diagnosis and treatment of pet tumors,and correct diagnosis is conducive to subsequent accurate treatment and rehabilitation.In order to clarify the pathological features and occurrence rules of mammary tumors frequently occurring in pet dogs,this study systematically made pathological diagnosis of 130 suspected canine mammary tumors collected in the laboratory in recent three years,and made differential diagnosis of malignant epithelial mammary tumors of special type,and analyzed their epidemiological characteristics on the basis of this.The results of this study provide technical support for the diagnosis and effective prevention of later canine mammary tumor.In this study,130 cases of suspected canine mammary tumors were prepared into paraffin sections and their morphological characteristics were observed.The results that 114 cases were mammary acinar or ductal tumors,7 cases were mammary hyperplasia,and 9 cases were other types of mammary tumors,such as leiomyoma and mast cell tumor.Among 114 cases of mammary tumors,34.2%(39/114)were benign and 65.8%(75/114)were malignant.Mixed adenoma and complex adenoma are the most common in benign tumors.Among malignant tumors,complex carcinoma and mixed carcinoma are the most common,among which 8 cases were malignant epithelial mammary tumors of special type.In addition to carcinosarcoma and squamous cell carcinoma,56.3%(40/71),38.1%(27/71)and 5.6%(4/71)of canines were diagnosed with grade I,grade II and grade III mammary carcinoma in malignant tumor.Tubular carcinoma,tubular papillary carcinoma,and malignant carcinoma originating from benign tumors are mostly grade I.Malignant epithelial mammary tumors of special type is easy to be confused with tumors from other tissues in morphology,such as fibrosarcoma and liposarcoma of mesenchymal origin.So a series antibodies including Vimentin,Pan ck,CK5,CK8,CK14,CK19,Pan calpoin,P63,Factor Ⅷ were used for immunohistochemical staining and special staining,including glycogen PAS staining and Alcian blue staining,was applied for differential detection to identify the origin of tumor cells.A method for identifying specific types of malignant epithelial mammary tumors has been established,which can be used to identify inflammatory mammary cancer,lipid rich carcinoma,spindle cell carcinoma,squamous cell carcinoma.The epidemiology of 114 confirmed cases of canine mammary tumor was analyzed,including the breed,age,sterilization and tumor site.The results showed that both benign and malignant tumors were favored by small poodles,followed by the most common breeds of benign tumors were mixed breeds,pekingese,bichon,etc.The most rare breeds were chihuahua,german shepherd,golden retriever,papillon.The most common breeds of malignant tumors are mixed breeds,bichon,Chinese pastoral dogs,etc,and the rarest breeds are deerhound,golden retriever,labrador,samoyed,English shepherd,etc.The onset age of benign tumors peaked at 8-9 years old,and the onset age of malignant tumors peaked at 10 years old.The incidence of benign and malignant tumors was very high in unaltered dogs.Most of the tumor sites in the dogs were single,and the incidence of the third to fifth pair of mammary glands was higher.The occurrence and development of mammary tumors are closely related to estrogen.In this study,the expression and distribution of estrogen receptor α in canine mammary tumors were analyzed by immunohistochemistry.The results showed that the expression in benign mammary tumors was higher than in malignant tumors,but the difference was not significant.Compared with other subtypes of tumors,ERα is low expressed in inflammatory mammary carcinoma and comedocarcinoma.In conclusion,based on the diagnosis of canine mammary tumor by histopathology,immunohistochemistry and special staining,this study evaluated the malignancy degree of mammary tumor,measured the degree of tumor invasion,and clarified the epidemiological characteristics of canine mammary tumor.The results of this study not only provide theoretical and technical support for the diagnosis and effective prevention and treatment of canine mammary tumors in veterinary clinic,but also contribute to the in-depth study of the pathogenesis of mammary tumors and the exploration of its potential therapeutic targets.