A melanocytoma is a benign tumor of cells that produce pigment—melanocytes. Only a histopathologist can determine the difference between a melanocytoma and a malignant melanoma.
As a general rule, tumors of the pigment-producting cells are usually benign where the skin is covered by fur and malignant in bare-skin areas such as lips or nail beds. The one exception are eyelids where these tumors are usually benign as well.
Further information: Melanocytic Tumors
A little over a year ago, I noticed a tiny bump on Cookie’s lower eye lid. At that time, it was so small that one could only see it at a certain angle and in a certain light. For a while I wasn’t sure whether there was something or I was just imagining things.
I brought it up during the nearest wellness exam to make sure it’s not something to worry about. Cookie’s veterinarian assured me it was nothing dangerous—most likely a cyst. It didn’t make sense to take any drastic measures in trying to get a better identification.
Little bump grows
Very slowly, the tiny bump kept growing. I discussed it with the veterinarian again, this time because I was concerned about it hurting the eye. It was, however, clearly growing in the direction away from the eye. Should we put Cookie under anesthesia just to remove a cyst that doesn’t seem to be in a way of anything? That didn’t seem to make any sense. Should Cookie need to go under for another procedure, we would remove it then.
Meanwhile, Cookie saw an orthopedic specialist to figure out why her shifting front leg lameness was not resolving. The specialist determined that her problem is a mild elbow dysplasia and we decided to treat it with platelet-rich plasma (PRP). Normally, the veterinarians perform this treatment under heavy sedation. There is a long story behind that but the long and the short of it is that
- the specialist recommended to repeat the PRP injections to boost the effect
- heavy sedation is a very bad option for Cookie
Further information: Front Leg Lameness in a Rottweiler: Cookie’s Sore Front Legs
General anesthesia instead of sedation
In order to give Cookie the booster PRP, we had a dilemma. The standard sedation protocol causes severe adverse effects in Cookie. The adjusted protocol carries a higher risk of dangerously slow heart rate, particularly in Rottweilers.
A well-designed general anesthesia would be safer than heavy sedation. Which is why decided to go with anesthesia instead. That would also allow us to take care of some house-cleaning items, such as removing the lump from Cookie’s eye lid and grab dental x-rays. So that’s what we decided to do.
Removing Cookie’s bump
Cookie’s veterinarian put a lot of consideration and care into making sure everything goes smoothly for Cookie. That day, Cookie was anesthetezied, received her PRP injections, got her dental x-rays, and the veterinarian excised her bump. She then sent the removed tissue to the lab for review. Don’t forget, up to that point we still thought it was a cyst. It is, however, better to be safe than sorry. I’d never have a lump removed from my dog without sending it for analysis to know for sure what it was.
While Cookie’s incision was healing, we received the report from the histopathologist—it was not a cyst after all. Fortunately, though, it was both benign and fully removed. Of course, the specialist couldn’t help including a note about some possibility of things going sideways.
Canine dermal melanocytic neoplasms with these histologic features are typically benign and complete surgical excision can be curative. In a small percentage of cases, tumors that are histologically benign can display locally infiltrative growth or distant metastasis.Fabiano Oliveira, DVM, MS
Since the excision was complete, we’re going to believe that Cookie is in the clear. Of course, should something change, we’ll take further steps. But her veterinarian believes that we’re done with this problem for good.
It again comes to show, though, you cannot judge a bump by its cover. I would have had it aspirated right away if it wasn’t in such a vulnerable location. We religiously aspirate all other lumps and bumps we find.
What Is That Bump on My Dog: Canine Lumps, Bumps, and Growths