Meibomian gland adenomas are small little skin tags that grow out of the glands along the eyelid. These also are benign but may require removal if they rub on the cornea, causing irritation.

Odds are your dog has one of these benign skin tumors; however, until you know what the mass is you cannot know this for sure. For this reason every lump should be brought to your veterinarian’s attention.

For the sebaceous adenomas and meibomian gland adenomas, your pet’s veterinarian can look and be confident about what he or she is seeing. For most tumors, though, visual inspection is not a definitive way to diagnose.

Unfortunately, with most lumps and bumps it requires a veterinary pathologist to look at cells from the mass under a microscope to determine whether the mass is something to worry about.

There are several ways we obtain these samples for the pathologist and as with everything, they each have their advantages and disadvantages.

The most benign sampling technique is the fine needle aspirate. As the name implies, this is where a small needle is inserted into the mass and a tiny sample is obtained. A syringe of air is used to push the sample out of the needle and onto a glass slide for submission to the pathologist. This technique is not only good for getting tissue from masses outside the body but with ultrasound guidance samples can be obtained from masses on the inside, too.

There are several advantages to the fine needle aspirate. The discomfort is minor as the needle used is smaller than those used to obtain a blood sample. Most internal organs do not have pain receptors so the skin prick is the only sensation even when sampling internal masses.

In most patients no sedation is needed, eliminating that risk and allowing the patient to go home immediately. At the laboratory, there is very little processing that needs to be done for the pathologist to assess the sample so this speeds up how quickly it can be examined.

The major disadvantage is the small size of the sample. Sometimes there are not enough cells present for a pathologist to be able to give a definitive answer.

Any time a needle is inserted anywhere bleeding may result. This is not a problem usually with skin masses but could be life-threatening for a mass sampled in the abdomen or thorax. Fortunately, in my experience, this is extremely uncommon.

The other method to obtain a sample is by getting a biopsy. This is where a piece, or better yet the entire mass, is removed and submitted. This larger sample allows the pathologist to look at not only the cells but also how the cells interact with each other.

When the entire mass is removed the edges can be examined to ensure we did not leave any tumor cells behind. When tumor cells are seen at the margin we know we have to go back and remove more if possible or recommend other therapies such as radiation or chemotherapy.

The major disadvantage is that a biopsy is a surgical procedure. Anesthesia is required and there is usually some post-operative discomfort.

With a fine needle aspirate, we often have results in 24 to 48 hours. With a biopsy, however, it is usually three to four days. Since biopsies are pieces of tissue, they must be cut into microscopically thin pieces for the pathologist to be able to evaluate them microscopically. The tissue must be processed over several days to allow it to be cut in this way.

You probably do not have anything to worry about with your dog but have your pet’s veterinarian take a look to be sure.

Dr. Henri Bianucci and Dr. Perry Jameson are with Veterinary Specialty Care LLC. Send questions to petdocs@po

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