RESUMO
Mammary invasive micropapillary carcinoma is a rare variant of mammary carcinoma that was recently recognized in dogs. The cytologic features and biologic behavior of such neoplasms in dogs have not yet been widely discussed in the veterinary literature. We report the clinical, cytologic, and histologic features of a canine micropapillary carcinoma in a 13-year-old female mongrel dog. The mammary region presented with extreme local pain, severe edema and erythema, and multifocal epidermal ulceration, which is typical for an inflammatory mammary carcinoma. Fine-needle aspirates were highly cellular and consisted of individual cells and papillary cell clusters with characteristics of malignant epithelial cells. Histologic examination revealed neoplastic cells arranged in small papillae without fibrovascular cores, sometimes inside clear lymphatic spaces, indicating lymphovascular invasion. Regional lymph node evaluation revealed metastatic cells. Due to deteriorating clinical condition the dog was euthanatized 5 months after mastectomy. At necropsy, metastatic neoplastic mammary cells were found in popliteal and mediastinal lymph nodes, the right femoral biceps muscle, liver, heart, lungs, and urinary bladder.
Assuntos
Neoplasias da Mama/veterinária , Carcinoma Papilar/veterinária , Neoplasias Mamárias Animais/patologia , Animais , Biópsia por Agulha Fina , Neoplasias da Mama/patologia , Carcinoma Papilar/patologia , Cães , Feminino , Linfonodos/patologia , Metástase LinfáticaRESUMO
Mammary tumors of female dogs have greatly increased in recent years, thus demanding rapid diagnosis and effective treatment in order to determine the animal survival. There is considerable scientific interest in the possible role of environmental contaminants in the etiology of mammary tumors, specifically in relation to synthetic chemical substances released into the environment to which living beings are either directly or indirectly exposed. In this study, the presence of pyrethroid insecticide was observed in adjacent adipose tissue of canine mammary tumor. High Precision Liquid Chromatography - HPLC was adapted to detect and identify environmental contaminants in adipose tissue adjacent to malignant mammary tumor in nine female dogs, without predilection for breed or age. After surgery, masses were carefully examined for malignant neoplastic lesions. Five grams of adipose tissue adjacent to the tumor were collected to detect of environmental contaminants. The identified pyrethroids were allethrin, cyhalothrin, cypermethrin, deltamethrin and tetramethrin, with a contamination level of 33.3%. Histopathology demonstrated six female dogs (66.7%) as having complex carcinoma and three (33.3%) with simple carcinoma. From these tumors, seven (77.8%) presented aggressiveness degree III and two (22.2%) degree I. Five tumors were positive for estrogen receptors in immunohistochemical analysis. The contamination level was observed in more aggressive tumors. This was the first report in which the level of environmental contaminants could be detected in adipose tissue of female dogs with malignant mammary tumor, by HPLC. Results suggest the possible involvement of pyrethroid in the canine mammary tumor carcinogenesis. Hence, the dog may be used as a sentinel animal for human breast cancer, since human beings share the same environment and basically have the same eating habits.