Ara's rare tumour

December 16, 2021

Ara was presented to Southfields in June 2021 for assessment of a thymoma, which is a relatively rare type of tumour that can develop just in front of the heart.

It had actually been surgically removed almost exactly a year before (which is the standard treatment for thymomas in dogs and cats), but there was some suspicion of a recurrence at Christmas 2020 and just prior to referral, it had clearly progressed significantly and had invaded and was very extensive within one of the main blood vessels in front of the heart. Sadly, further surgery was no longer viable. Poor Ara also had a small lung nodule removed at the time of the original surgery, which actually revealed she had a second type of unrelated lung cancer!  Luckily, it was expected that surgery for this type should be adequate.

The plan was for Ara to have radiotherapy (the use of high-energy x-rays that are targeted to the tumour to damage the cancer cells and shrink the tumour) to treat the recurrent thymoma, so she had a CT scan to help plan the treatment. Unfortunately, this revealed that Ara had started to build up a significant amount of pleural effusion (fluid accumulation between the chest wall, surrounding the lungs). This was likely mainly due to the blockage of this big blood vessel by the tumour. This needed draining in the short-term as, after a few days, it started to noticeably cause some breathing changes. Ara had a special catheter sutured into the space around the lungs (pleural space) to aid the regular drainage that was anticipated.

Ara underwent a 3-week course of radiotherapy, which was planned by one of our double-boarded cancer specialists, James Elliott, who is a specialist in both medical and radiation oncology. The goal was to target the tumour and any tissue nearby at risk of harbouring any cancerous cells. Thymomas typically respond well to radiotherapy and usually show at least some shrinkage. Ara tolerated this very well and the catheter was removed as she was no longer developing excessive fluid in her chest. Since completing her treatment, no further fluid has had to be drained from her chest and she has had a fantastic quality of life at home (as you can see from the photos).

Ara recently underwent a CT scan, which revealed the tumour had shrunk. This was fantastic news. We are so pleased that she continues to do well and wish her all the best for the future.

Radiotherapy can be an excellent tool, particularly in cases where surgery has failed or would not be expected to result in optimal tumour control by itself. It can be particularly effective in cases like Ara’s, where surgery is not feasible due to the tumour’s association with important blood vessels.