Splenic Tumors in Dogs – a Lay Person’s View

February 24, 2011

Bad things happen in the spleens of dogs. I don’t know why, I just know they do.

Medically speaking, canine splenic masses typically start as unremarkable “nodules”. From there, they often transform into one of two types of masses: hemangioma (a benign tumor) and hemangiosarcoma (a malignant cancer). Other types of masses also occur but these two are the most common. Unfortunately, because the spleen is a vascular organ, even the benign ones often have tragic results.

In my experience (and that of many dear friends), splenic masses result in one of the following three outcomes, often without diagnosis or warning:

  1. They rupture and the dogs bleed to death
  2. They metastasize and the dogs die of cancer in other organs (lungs, brain)
  3. They get discovered by pure dumb luck and are dealt with surgically before #1 or #2 can occur

Scenarios #1 and #2 are tragic and I have far too many friends who have experienced one or the other. To protect the feelings of those who have suffered these tragedies, I will not name them. But I will give the following first-hand examples of #3 (with permission) – all three of these dogs were diagnosed accidentally as a result of unrelated events:

  1. Jasmine, my own 13-yr-old, had a frightening vestibular event (i.e. doggy vertigo) a few weeks ago. I have since learned that this is a rather common idiopathic condition in older dogs, but the neurologist that examined her determined that she wasn’t “classically vestibular”. In pursuing a differential diagnosis, an abdominal ultrasound was performed revealing a large abdominal mass. Urgent exploratory surgery resulted in the excision of a “fully-encapsulated splenic mass with no evidence of other organ involvement.” Final pathology results are still pending, but the preliminary assumption is that the surgery was curative. There is additional background to this story as you’ll see below.
  2. My friend Sarah, who specializes in canine rehab and massage, was routinely massaging her 14-yr-old Cruiser one night and felt a bulge under her rib cage. This lump was only apparent to sensitive hands and only when the dog was on her back. On examination, her doctor couldn’t even feel it but abdominal ultrasound revealed a splenic tumor which was then surgically excised. The dog lived another great year and eventually succumbed to complications of unrelated kidney failure.
  3. Just last week, my friend Liza’s 7-yr-old Taiko had an intestinal obstruction that required emergency surgery. While his belly was open, the surgeon observed a nodule on the spleen and elected to perform a splenectomy. Pathology report on the lesion suggested that it would have likely transformed into a splenic tumor (probably hemangioma) had it gone undetected.

Here’s a little more background on Jasmine’s story: in April of 2008, she spent a couple of days at Davis for a bout of hemorrhagic gastroenteritis (HGE). During her stay she had an abdominal ultrasound. They found nothing to explain the HGE, but did note some other abnormalities: a cyst on the liver and two nodules on the spleen. We were advised to follow up with another ultrasound in about a year. So we did. A scheduled ultrasound in June 2009 reported that the liver cyst was unchanged and the two splenic nodules were nowhere to be found. Excellent news, or so we thought. Not long after that I began having theoretical discussions with friends about the merit of routine ultrasounds, but we didn’t bother to do another one in the summer of 2010. Fast-forward to February 2011 and the crisis described above.

I found a terrific article that explains in much more detail what I’m talking about: http://www.marvistavet.com/html/body_splenic_masses.html. The most telling quote for me in this article is this: “[If the dog has a splenic mass and you choose not to remove the spleen], eventually the dog will have a bleed from which he cannot recover.”

So what’s my point? Dogs die from splenic masses, often unnecessarily. It doesn’t matter whether they are malignant or benign. Sure, malignant masses affect other organs and the dog will eventually die anyway. But benign doesn’t mean harmless, it just means non-cancerous – benign tumors can still grow like crazy and rupture. In fact, I learned a parodoxical reality: the larger the splenic mass, the more likely it is benign because the dogs don’t survive the malignant ones long enough for them to grow large. Regardless of size or type, ALL splenic masses have the potential to rupture and cause death from hemorrhage. They are ticking time bombs, pure and simple. Isn’t it time we acknowledge this fact and start preemptively screening for the problem?

Lessons learned:

  1. Splenic nodules do not just disappear. I don’t know where Jasmine’s were in June 2009, but I’m sure now that they were lurking somewhere.
  2. Splenic nodules transform, and nothing good comes from that transformation. Even if they transform into benign masses, they can still rupture and cause catastrophic hemorrhage.
  3. If at all financially-feasible, we should consider doing annual diagnostic ultrasounds on our aging dogs to avoid these tragedies. They are non-invasive and require only a mild sedative (if even that).

I have a mammogram every year, and I’m going to do my best to ensure that my older dogs get the same consideration.