Metastasis of Mammary Carcinoma in Bitches: Evaluation of the Sentinel Lymph Node Technique

In recent years the development of extremely accurate techniques for the removal of lymph nodes has been seen, such as the Sentinel Lymph Node Biopsy (SLNB) technique. The technique is based on the staggered progression occurring in the lymphatic drainage of neoplasias, and is currently the main prognostic and diagnostic factor in women suffering from mammary carcinoma. This research aims at assessing the sentinel lymph node biopsy accuracy in female dogs suffering from mammary carcinoma. Forty-one dogs with cytological diagnosis of the tumor were used in the research. After injecting a Patent Blue V dye, mastectomy was conducted jointly with lymphadenectomy (for both sentinel and non-sentinel lymph nodes). The material was then serially sectioned and microscopically evaluated by routine H&E stain and immunohistochemical study with the markers for pancytokeratin AE1/AE3 and myoepithelial cells CK14. The study revealed that 46.3% (19/41) of the animals presented nodal metastasis. The sensitivity and specificity values found for SLNB were respectively 89.5% and 100%, with a kappa coefficient of 0.90 and p < 0.0001. Therefore, the SLNB technique offers high sensitivity in the early detection of metastases, allowing higher precision in the staging of oncological patients and, therefore, offering higher chances of survival.