Melanocytoma in a Dog: Cookie’s Eyelid Bump that Was Not a Cyst

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

Melanocytoma in a Dog: Cookie's Eyelid Bump that Was Not a Cyst

Cookie’s story

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.

Melanocytoma in a Dog: Cookie's Eyelid Bump that Was Not a Cyst

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.

Related articles:
What Is That Bump on My Dog: Canine Lumps, Bumps, and Growths

Further reading:
Melanocytic Tumors

Categories: Dog health advocacyLumps and bumpsMelanocytomaReal-life StoriesSymptoms

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Jana Rade

I am a graphic designer, dog health advocate, writer, and author. Jasmine, the Rottweiler of my life, was the largest female from her litter. We thought we were getting a healthy dog. Getting a puppy from a backyard breeder was our first mistake. Countless veterinary visits without a diagnosis or useful treatment later, I realized that I had to take Jasmine's health care in my own hands. I learned the hard way that merely seeing a vet is not always enough. There is more to finding a good vet than finding the closest clinic down the street. And, sadly, there is more to advocating for your dog's health than visiting a veterinarian. It should be enough, but it often is not. With Jasmine, it took five years to get a diagnosis. Unfortunately, other problems had snowballed for that in the meantime. Jasmine's health challenges became a crash course in understanding dog health issues and how to go about getting a proper diagnosis and treatment. I had to learn, and I had to learn fast. Helping others through my challenges and experience has become my mission and Jasmine's legacy. I now try to help people how to recognize and understand signs of illness in their dogs, how to work with their veterinarian, and when to seek a second opinion. My goal is to save others the steep curve of having to learn things the hard way as I did. That is the mission behind my blog and behind my writing. That is why I wrote Symptoms to Watch for in Your Dog, which has turned out being an award-winning guide to dog owners. What I'm trying to share encompasses 20 years of experience.

  1. Hi, I just had the exact same thing with my rottweiler. She also had 2 bumps that were removed and sent to analysis. The vet just called me and told me that it was melanocytoma and that it even though it was benign it was good to have it removed. May I ask if you have any follow up infos that you can share? Was the problem solved for good? Thank you 🙂 best regards

    • So far it has not returned; so it seems it is gone for good. I suspect the trigger might have been some of the deer fly bites–they really love going after her eyes.

  2. I am glad to hear that it turned out to be something benign. I know that fear that comes with finding an unexplained lump, we’ve been there with our pets before. Your mind races and all the most negative possibilities start to haunt you. Cookie is lucky to have such a great owner doing everything to keep her happy and healthy!

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