Testing Testing 1...2...3? (Part 3)

Back to balancing Precious’s thyroid (Continued from Part 1 and Part 2) 

I had increased her thyroid medication.  Her owner, who lives on the other side of town, asked if she could have the test run at her previous vet, since she lives much closer there.  I said that was fine.  She brought Precious there, and the vet ran the FT4 test, and also ran a chemistry panel  to see if the liver enzymes had changed at all.  The good news:  the FT4 was now normal and we could proceed with the anesthesia.  The worrisome news: the liver enzymes were still high; in fact, they were even higher than before.

Precious arrived at our hospital and we did the endoscopy as planned.  We also biopsied the liver.  She recovered uneventfully and we sent her home that evening.  Again, I was envisioning two likely scenarios:  we had inflammatory bowel disease with secondary inflammation of the liver, or we had low grade intestinal lymphoma, with lymphoma in the liver as well.  

Of course, nothing is ever what you expect.  The gastrointestinal biopsies revealed moderate inflammatory bowel disease in the stomach and intestine, and low grade lymphoma in the liver!  This is an odd combination.  I suppose it is possible to have these two conditions like this, but this is just not the usual case.

One possibility is that the intestinal biopsies weren’t accurate, and that the cat truly has low grade lymphoma in the intestine as well.   It is universally understood that actual full-thickness biopsies of the gastrointestinal tract are the best and most accurate biopsy specimens available.  To obtain these, however, the cat needs to undergo abdominal surgery, and most clients dread the idea of their cat having this surgery.   Endoscopy can provide an accurate diagnosis if the endoscopist is very experienced, and multiple samples are taken.  Our endoscopist is indeed VERY experienced, and he gets at least 8 samples from every site.  

Another possibility is that the liver biopsy specimen was read incorrectly, but I doubt this.  The pathologist reading the samples is the one we know and like best, and his diagnoses always seem to correlate with what we see clinically.  

I called Precious’s owner and gave her the news.  She was dejected, of course.  I told her, however, that low-grade lymphoma is treatable, and that cats tend to do pretty well.  Exactly how long a cat survives varies from cat to cat, but low-grade lymphoma is not very aggressive (hence the name “low grade”) and that cats can survive months or years.  She was encouraged by this information and was anxious to start treating.  

Frankly, in this case, it doesn’t really matter if the cat has IBD vs. lymphoma in the gastrointestinal tract, because the presence of lymphoma in the liver dictates our therapy.   We treat inflammatory bowel disease with prednisolone.  We treat low grade lymphoma with prednisolone and leukeran.  We’re going to treat Precious with prednisolone and leukeran, and see how she does.  I’ll see her back in two weeks to do a complete blood count to make sure the leukeran isn’t bothering her bone marrow.  A month after that, I’ll check out her liver enzymes to see if they’re coming down in response to the treatment.  About two months after that, we’ll ultrasound her again, to make sure everything looks status quo in the abdomen.  Low-grade lymphoma is unlikely to spread anywhere, but it’s good to do ultrasound just to check. 

The best (and most puzzling) thing about this entire case is that Precious feels fine!  She may have intestinal and liver disease, but you wouldn’t know it by the way she looks and behaves.   A cat who starts out on chemo looking good and feeling well is likely to respond better than a cat who is debilitated because the cancer has started taking its toll.  I’ll keep you posted on how she does over the next few months (hopefully years).