< Home



< Back

33rd Annual Scientific Meeting proceedings

Stream:   |   Session: Short Communications ST + Oncology
Date/Time: 07-07-2023 (16:45 - 17:00)   |   Location: Chamber Hall
The role of regional versus sentinel lymph node biopsy in cats with integumentary mast cell tumors
Chiti LE1, Gariboldi EM2, Stefanello D2, Nolff MC1
1University of Zurich, Zurich, Switzerland, 2University of Milan, Milan, Italy.

Integumentary mast cell tumor (MCT) is regarded as a biologically non-aggressive cancer in cats. However, nodal metastases have been recently reported in 20-58.8% of cases. The aim of this study is to assess the impact of regional (RLN) versus sentinel lymph node (SLN) extirpation in cats with MCT.

Materials and Methods
25 client-owned cats presented for MCT excision were retrospectively enrolled. Blinded RLN excision or SLN excision guided by near-infrared fluorescence (NIRF) or by radiopharmaceutical and methylene blue (MB) was performed concurrently. Retrieved variables were: signalment, number of MCT, location and number of excised SLN/RLN, correspondence or not between SLN and clinically expected RLN. Histopathological reports were revised for status of the node, tumor grade and margins.

Six cats had multiple MCT, 19 had a single MCT. The RLN was excised in 18 cats, while in 7 the SLN was removed after mapping with NIRF (n=5) or radiopharmaceutical and MB (n=2). The SLN did not correspond to the RLN in 71.4% of cases. Multiple RLN were removed in 2/18 cats, and multiple SLN in 5/7 cats. At histopathology, all MCT were low-grade, excised with tumor-free margins. Metastases were detected in 53% of RLN and in 85.7% of SLN.

Despite all MCT being low-grade, nodal metastases were frequently detected, suggesting that lymphadenectomy should be implemented in feline MCT. The high non-correspondence rate between the SLN and RLN, and the higher rate of nodal metastases encountered in SLN, suggest that SLN mapping could allow for a more accurate staging.

Back to the top of the page ^