Peer-reviewed veterinary case report
Methylene blue dye helps find lymph nodes in dogs with low-grade mast
By Zanardi, S et al.·Published in The Journal of small animal practice·2025·Department of Veterinary Medical Sciences, Italy·View original on PubMed →
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Original publication title: Intraoperative methylene blue staining is effective as a single mapping technique in the identification of sentinel lymph nodes in dogs with low-grade mast cell tumours.
- Species:
- dog
Plain-English summary
A group of 25 dogs with low-grade mast cell tumors underwent surgery to remove the tumors and check for cancer spread to nearby lymph nodes. During the procedure, a blue dye was injected near the tumor to help identify sentinel lymph nodes, which are the first nodes that cancer might spread to. The dye successfully stained 29 out of 53 lymph nodes, and all lymph nodes that were stained had cancer, while the unstained nodes were found to be non-cancerous. This method proved to be effective and safe, making it a good option for detecting cancer spread in dogs with mast cell tumors.
People also search for: dog mast cell tumor treatment · sentinel lymph node mapping in dogs · blue dye for dog cancer surgery
Abstract
OBJECTIVES: The aim of this prospective study was to assess the association between methylene blue staining pattern and the presence of histologic nodal metastasis in dogs with low-grade mast cell tumour in low-resource settings for the efficient diagnosis of lymphatic spread. METHODS: Dogs with a single, cytologically low-grade mast cell tumour and no documented distant metastases were prospectively included and underwent surgery. Along with primary mast cell tumour removal, intraoperative sentinel lymph node mapping with peritumoral mast cell tumour injection and regional lymph node excision, regardless of whether blue dye was visible in the lymph node, were performed. Association between the lymph nodes with dye uptake (stained) and their metastatic status was evaluated. RESULTS: Twenty-five dogs were enrolled, and at least one stained lymph node was identified in 22 (88%) of them. A total of 49 lymphocentres were surgically inspected, and a total of 53 lymph nodes were removed. Twenty-nine (54.7%) lymph nodes were stained, and 24 (45.3%) were unstained. Among the 29 stained lymph nodes, there were seven (24.1%) HN0, seven (24.1%) HN1, seven (24.1%) HN2 and eight (27.7%) HN3. Among the 24 unstained lymph nodes, 17 (70.8%) were HN0 and seven (29.2%) were HN1. No complications related to methylene blue injection were recorded. CLINICAL SIGNIFICANCE: Peritumoral methylene blue injection is a cost-effective alternative technique for detecting sentinel lymph node for dogs with mast cell tumours, particularly in economically constrained settings. All metastatic lymph nodes (HN2/HN3) were stained, and all unstained lymph nodes were non-metastatic (HN0/HN1).
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Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/39870104/