The recent literature supports the sentinel lymph node (SLN) biopsy in dogs with MCT due to discrepancy with the regional lymph node and the high percentage of occult metastasis. However, the SLN biopsy includes additional anesthesiologic, diagnostic, and surgical procedures, and additional costs. The study aimed to assess the association between clinicopathological variables and SLN status, determining the identification of dogs at lower risk of SLN metastases. Dogs with integumentary MCT were admitted to the lymphoscintigraphic mapping and subsequent biopsy of SLN. The association between clinicopathological variables of MCT and SLN status was statistically tested, both considering occult and overt metastasis together (HN2-HN3) and overt metastasis (HN3) alone. Fifty low-grade cutaneous MCT and 16 subcutaneous MCT were included. A small to moderate association between integumentary MCT ≥ 3 cm and HN2-HN3 SLN was found. A strong association of integumentary MCT dimension and subcutaneous MCT with HN3 SLN occurred. Dimension of low-grade cutaneous and subcutaneous MCT seems to correlate with SLN status, but additional study should confirm this data before excluding small MCT to the SLN biopsy. On the contrary, the study results induce a solid suggestion for mapping and biopsy of the SLN in MCT > 3 cm and subcutaneous MCT.

Lymph node status is an important prognostic factor in multiple oncologic conditions in humans and companion animals. In addition, the resection of the affected nodes can have a substantial therapeutic effect on various cancer subtypes in both species. Given the impact on prognosis and management, it is paramount to identify and remove affected nodes. While this can be achieved by removing predefined patterns of nodes (regional lymphadenectomy/resection of defined lymphatic stations), modern approaches increasingly utilize sentinel node mapping to identify the draining nodes to decrease the mortality of lymphadenectomies. Recent studies have shown that dogs have more comparable anatomy of the lymphatic system to humans than other animal models such as rodents or pigs. Given the fact that dogs develop spontaneous cancer types that share several similarities to their human counterparts, they represent a valuable translational model. The management of the lymphatic basin and sentinel node mapping have gained increased attention in veterinary surgical oncology in recent years. The present review aims at summarizing the resulting findings and their impact on patient management.