Ask a vet: I found a lump, now what?

Words by:

Lindsay Wolcott, BVMS — Associate IndeVet

If you are a nervous-nelly of a dog-mom like I am you know every inch of your dog. So when you find a new lump you frantically call your veterinarian for an appointment. Certainly it needs to be removed and quickly?

Not necessarily. Every mass is different. If a lump is hard, painful, rapidly growing, ulcerated, or is in a location that is dangerous, for example; the eye, locations of lymph nodes, or mammary glands the receptionist will work with you to get an appointment sooner than later. Slow growing, non-painful masses can usually wait til the next available appointment.

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What to expect at your vet appointment

During the appointment your vet is going to ask you a couple of questions while doing a full physical exam on your pet. This is a sample list of questions and is not exhaustive:

When did you first notice the lump?
How fast does it appear to be growing? i.e. days or months?
Is it painful to touch? Does the pet try to bite or scratch it?
Has your pet had similar lumps before? Any previous surgeries or testing?
Where on your pet is it? ( if your pet has long hair it might not be obvious)
Was your dog exposed to anything new in the past few weeks?
Did your pet have any vaccines in the past week?
Was your pet stung by a bee or wasp recently?

The answers to these and other questions as well as a thorough physical exam will help us narrow down our differential list.

During the exam we are checking the mass for its size, shape, firmness, any heat or pain, and ulceration among other criteria to help determine the likelihood of different conditions.

For example, a soft mobile mass under the skin of an older lab is more likely to be a benign lipoma (extremely common BTW) vs a firm mass behind the stifle or under the jaw has a higher likelihood of being of lymphoma.

A small bump on the shoulders or hips with a history of recent vaccination is likely the spot where the vaccine was given. An ulcerated area of skin or a soft fluid filled lesion could be an infection or a cyst, respectively.

What happens if the lump requires further evaluation?

If it is determined that the mass needs to be evaluated further there are several methods available.

The first is these is called a fine needle aspirate or FNA. In order to take a sample your vet will stick a needle in the mass and spread the cells on slides to send to the pathologist who will then look under the microscope to determine cell line and check for malignancy.

More often than not, if the mass is big enough and the patient patient enough, a FNA is sufficient for a diagnosis. If a mast cell tumor is suspected your vet will give injectable benadryl to limit risks of reactions prior to getting the sample. I do this with a multitude of different masses as mast cell tumors can mimic several other diseases on presentation.

However, there are some masses that do not exfoliate well with just a needle. If we need a bigger sample then a punch biopsy is the next step.

We can do that with either local anesthesia or sedation. With this type of sample we take a larger piece, roughly the size of an eraser on a pencil, which is evaluated at a lab.

Now, if that still doesn’t give us an answer and/or the mass is going to be removed anyway then we proceed with general anesthesia to surgically remove the mass and send the whole piece for histopathology. This will give us a definitive answer and let us know if we got clean margins during surgery.

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Treatment for when you find a mass

The results of these tests will help guide treatment plans. Benign slow growing masses, like lipomas, are usually left alone unless it is bothering the pet in which case we remove them.

Cancerous masses have several options these days including chemo and radiation, both of which are done at referral centers. Depending on the tumor type sometimes removing the mass during surgery is curative.

More often than not a general practitioner can take the samples and do mass removals at the clinic. However, there are masses who size and location are best left to a specialist in soft tissue surgery or surgical oncologist to remove.

For example, large masses in the arm pit are higher risk masses to remove as the brachial plexus, which consists of major veins, arteries and nerves, is right there. If the plexus is damaged it can lead to paralysis of that limb. Your primary vet will be able to best guide you in these situations and set up the referral if needed.

In summary

So next time you find a lump on your pet go through the questions above before calling the office. You will be better prepared when the receptionist asks you questions so they figure out how quickly they need to get you in. Your vet will do a full physical exam on your pet and recommend different diagnostics based on their findings. With the advances in vet med over the years there are many treatment options available depending on the diagnosis.

PS: Diagnostics are always recommended because my hands are not magic. I cannot tell what any mass is just by feel, even if I have my suspicions. I wish I could though, that would make a diagnosis a snap of the fingers.

Dr. Lindsay Wolcott is an Associate IndeVet practicing in South Carolina.