Detection of mammary adenocarcinoma metastases in a cat through 99mTc-thymine scintigraphy

Abstract

Mammary adenocarcinomas with metastases are more common in dogs than in cats. Their incidence is 1 in every 4,000 cats. In routine veterinary practice, laboratory exams for diagnosis of these neoplasms are nonspecific and scarcely used. Even though invasive procedure, biopsy, and histopathological findings are the gold standards that define the clinical approach, the clinical evaluation, and image assessment lead the way to the proper treatment, especially when surgical intervention is a possibility. This study describes the clinical signs, histopathological aspects, radiological and scintigraphic findings of a cat with mammary adenocarcinoma and metastases evaluated one hour after intravenous administration of 99mTc-thymine. Our focus was not to discuss the pathological aspects of the disease but the Nuclear Medicine role in metastases detection. Metastases, when lesser than 4mm, could go unnoticed by radiological exams, whereas scintigraphy may detect them. Using 99mTc-thymine scintigraphy, we successfully detected unsuspected metastases in the lungs, liver, and right kidney. Early diagnosis is the key to a better rate of survival due to the given treatment and prognostic. Hence, we strongly recommend the use of 99mTc-thymine scintigraphy as a complementary tool for breast cancer diagnosis in veterinary care.

Sonographic Assessment of the Normal and Abnormal Feline Mammary Glands and Axillary and Inguinal Lymph Nodes

“…In the G2, mammary pathology was detected at an average of 7.4 years of age, characterizing earlier involvement than in most published studies, which mention an average of 10 to 14 years of age [ 3 , 12 , 17 , 18 ]. In our study, 80% of the cats had nodular involvement in multiple mammary glands, similar to the reviewed literature [ 1 , 9 , 19 – 21 ].…”

“…It is estimated that 50% to 70% of cats with malignant mammary neoplasms without signs of metastasis at clinical evaluation will still develop metastatic lesions [1,7,19,25]. In addition, there are other imaging methods much more sensitive to detect small metastatic lesions as computed tomography [26][27][28][29][30][31][32], magnetic resonance imaging [26,29], and scintigraphy [1,25]. e presence of accessory lymph nodes in cats has been described in the literature, and they can present from 1 to 4 lymph nodes performing axillary and inguinal drainage of mammary glands [33,34].…”

“…One patient with a primary thoracic mammary nodule had a miliary interstitial lung pattern identified by a thorax radiographic study. However, the result of a normal radiographic examination is not synonymous with the absence of possibly metastatic lesions [ 1 , 7 , 25 ], as chest radiographs are only able to detect pulmonary nodules larger than 4-5 mm [ 1 ]. Abdominal ultrasound may also show changes in the structure and morphology of the abdominal organs [ 7 , 26 ].…”

“…In veterinary medicine, neoplasia has been identified as one of the main causes of pet mortality and occurring predominantly in old age [1][2][3]. Felines are mainly affected by cutaneous neoplasms, lymphomas, and mammary neoplasms.…”

Foreign experience in veterinaryapplication of scintigraphy

“…Когда речь идет о непродуктивных животных (кошках и собаках), данный метод визуальной диагностики применяют для выявления морфофункциональных нарушений почек, щитовидной железы, наличия портосистемных шунтов в печени. В спортивном коневодстве сцинтиграфию используют для диагностики патологий опорно-двигательного аппарата (хромота, переломы костей таза) [3][4][5].…”