Case of the Month! Nov 2012

Our November Case of the Month is brave Wooster Duerden who at 18 months old suddenly developed a mass in his abdomen. Wooster is normally your typical into everything young Siamese cat – very vocal and playful.  So after a couple of quiet days his owners rightly became suspicious, lethargy was not normally on Wooster’s daily ‘to do’ list!  He was still eating normally but on day four of being more quiet his owners observantly noted that his abdomen was changing shape and getting larger.  Despite not showing any signs of sickness they rightly decided to bring him to the surgery that evening. On examination Wooster was very lively – a trip to the Vets always takes your mind off things – but he had a tangerine sized lump in his abdomen.  It was not painful and surprisingly the rest of his examination was completely normal. He was booked in straight away for a mass investigation.  Survey chest x-rays revealed no sign of any lumps within his lungs (secondary metastases) but these x-rays clearly show a 10cm size mass in his abdomen – images can be found in the gallery below. Given there was no sign of any spread and had normal blood parameters (including FeLV/FIV testing) it was decided to take him straight to surgery and try to remove this mass.  As you can see in the pictures below the mass was enormous and was surrounding his small bowel.  Very luckily for Wooster it was not blocking his bowel lumen so eating and digesting his food had still been able to go ahead as usual. The entire lump was removed including the bowel it surrounded.  In this case the tumour had developed from the muscular wall that makes up the bowel wall.  Worryingly there was also evidence that his lymph nodes were enlarged so these were removed too for testing. Recovery from his surgery was uneventful and he bounced back quickly.  The operation site had some bruising postoperatively but most of this was due to Wooster’s acrobatics at home, very cross that he was not allowed outside! The bowel mass and lymph node were analysed by a specialist histopathologist.  Unfortunately as expected the mass was a Lymphosarcoma – this is a type of cancer where lymphocytes (a type of white blood cell) become malignant and rapidly divide.  Sadly this seems to be a genetic problem and it is known that Siamese cats can be prone – although to develop lymphosarcoma at such a young age is unusual. Thankfully for Wooster the statistics are in his favour.  Cats under 4 years old that are FeLV negative tend to do very well with oral medication that prevents the lymphosarcoma from returning.  These drugs are commonly known as chemotherapy and understandably carry a certain stigma.  In human medicine chemotherapy is used to achieve a cure using very high doses of these drugs.  With our patients we aim for a quality of life and give much lower doses of the medication to avoid hair loss, nausea and the other signs commonly associated with chemotherapy patients in people. 96% of Cats recieving the Chlorambucil High Dose Pulse Protocol show successful remission and can live for many years with an excellent quality of life. Wooster is receiving daily prednisolone tablets and once every two weeks has a blood test to check his blood count.  If it is normal he then receives his chemotherapy tablets (Chlorambucil)- normally wrapped in smoked chicken so he is very happy!  He is living a normal life – going outside and is up to all the mischief you would normally expect an 18 month old Siamese to be doing.  He has a lush coat and has put on weight, loving his food and the copious amounts of fuss that he is getting at the moment. Although it is early days and we are watching Wooster very closely his owners report that he is better than they can ever remember him.  In Australia they have researched this type of lymphoma very closely in Siamese cats and found there is a genetic link.  If he responds well to the medication, which he certainly is doing at the moment, then we hope that he will live several years to come very happily.  Best of all 33% of cats that stay in remission for over two years can go onto a complete recovery.