https://www.vetsurgeon.org/f/clinical-questions/30089/weird-feline-case 14yo dsh cat diagnosed hyperthyroid and on thyronorm bid for last 3-4 months. Planning for I 131. But this developed. Biopsies taken- results below. Sounds as though the pathologists are unsure as well, so wondered if any of you had any thoughtsen-USTelligent Community 10https://www.vetsurgeon.org/thread/234198?ContentTypeID=1Thu, 02 Dec 2021 17:20:17 GMT146601cc-3922-4be7-9974-7e1d4e45a66b:4d475019-0b07-4915-9437-36fa5582d3ffKate Richardson<p>Thanks Rodney, that was our thoughts even before the biopsy results, so we were quite surprised. We had already stopped the methimazole just in case but my colleague reports the lesions have progressed extensively, so it may neoplastic after all. She has been referred now so will let you know the outcome.</p><div style="clear:both;"></div>https://www.vetsurgeon.org/thread/234196?ContentTypeID=1Thu, 02 Dec 2021 13:01:41 GMT146601cc-3922-4be7-9974-7e1d4e45a66b:5debc207-e845-4f41-ad5b-f8ce11698a67Rodney Ayl<p>I think this is less likely to be representative of a sarcoma, based on its presentation. I would consider a drug associated gingival proliferation that could be caused by various processes, which could be investigated - see article below. Alternatively stopping the methimazole and completing the RT for the hyperthyroidism, could resolve the problem.</p> <p><a target='_blank' href="https://www.ncbi.nlm.nih.gov/books/NBK538518/#__NBK538518_ai__">www.ncbi.nlm.nih.gov/.../</a></p><div style="clear:both;"></div>