https://www.vetsurgeon.org/f/clinical-questions/23907/long-term-use-of-masivet Dear All, Wondered if any of you had experience of using Masivet for long periods of time as the datasheet doesn&#39;t tell you how long treatment is recommended for? We have a 12 year old Lab who has already been on it for 6 months. She had 2 MCTs removeden-USTelligent Community 10https://www.vetsurgeon.org/thread/153231?ContentTypeID=1Fri, 19 Feb 2016 09:21:04 GMT146601cc-3922-4be7-9974-7e1d4e45a66b:9f4e10e0-73da-4e7b-86f4-4e589ce0ab30Gerry Polton<p>Hi</p> <p>TO answer the question about mast cells in a lymph node aspirate, we know that it is notoriously difficult (actually it is impossible) often to discriminate metastatic mast cells from normal trafficking mast cells in a lymph node on cytology alone. If there are simply thousands of them we assume it&#39;s neoplasia. If they are clearly atypical the same. However, usually we are talking about small numbers of normal-looking well-granulated mast cells. We have to exercise judgement in these cases.</p> <p>With a low-grade completely excised tumour as described, I think it would be the wiser choice to withdraw masitinib. There is a continuing risk of adverse effects from its continued use that is balanced against the risk of progressive disease if you withdraw it. In my opinion, you are at a point where the balance of risks falls in favour of treatment withdrawal.</p> <p>Yours</p> <p>Gerry</p><div style="clear:both;"></div>https://www.vetsurgeon.org/thread/153217?ContentTypeID=1Thu, 18 Feb 2016 21:06:32 GMT146601cc-3922-4be7-9974-7e1d4e45a66b:fa067a9e-65f2-4e6e-b8cf-2342970732feRob Loxley<p>[quote user=&quot;scatty&quot;]put on to Masivet as a precaution due to mast cells being identified on cytology from the left popliteal lymph node[/quote]</p> <p>Does identification of a few mast cells on a draining lymph node equate to definite metastatic spread?</p><div style="clear:both;"></div>