Evaluation of Surgical Aid of Methylene Blue in Addition to Intraoperative Gamma Probe for Sentinel Lymph Node Extirpation in 116 Canine Mast Cell Tumors (2017–2022)

Methylene Blue (MB) is combined with radiopharmaceutical for intraoperative sentinel lymph node (SLN) mapping, but its role during SLN extirpation has not been investigated yet in veterinary medicine. The aim of this study was to assess whether MB increased surgical detection beyond the use gamma-probe (IGP) alone clinically node-negative dogs mast cell tumors (MCTs) following lymphocentrums (SLCs) via preoperative planar lymphoscintigraphy. Dogs enrolled underwent MCT excision and SLC exploration guided by both IGP. Data recorded each were staining (blue/non-blue), radioactivity (hot/non-hot), histopathological status (HN0-1 vs. HN2-3). A total 103 bearing 80 cutaneous, 35 subcutaneous, 1 mucocutaneous MCTs included; 140 SLCs explored, a 196 SLNs removed. Associating IGP raised rate from 90% 95%. 44% metastatic: 86% blue/hot, 7% only blue, 5% hot, 2% non-blue/non-hot. All HN3 hot. Combining can increase MCTs; nonetheless, all nodes identified dissection should be removed, as they might unstained metastatic.