Skin Masses:  Don’t Just Watch and Wait 

Skin lumps or masses are a very common occurrence in dogs.  Skin masses may occur in young dogs, but are more likely to be found in middle-aged to older dogs.  Masses may be found either under the skin or on top of the skin, and may grow quickly, slowly, or not at all once they are diagnosed.

It is important to have skin masses checked out by your veterinarian because they can be either benign or malignant.  Some of the more common benign skin masses are lipomas (fat cells) and sebaceous adenomas or cysts. However, there are a variety of potentially malignant skin masses that are common in dogs, including mast cell tumor, soft tissue sarcoma, or hemangiosarcoma.  Unfortunately, it is not possible to make a diagnosis based on the look or feel of the mass alone. Therefore, testing of the mass is needed to determine if the mass is benign or malignant. 

No one can look at a mass or feel a mass and know what it is – so here is some information about some tests that can determine what the mass is on your pet.

Your veterinarian may recommend a simple test called a fine needle aspirate to start the diagnostic process.  This involves sampling the mass with a small needle and then evaluating cells collected from the mass on a slide.  Your veterinarian may do this in the clinic, or may recommend sending the slides out to a pathologist for a definitive diagnosis.  This test is fortunately quick, painless, and typically does not require sedation or anesthesia.  

After a FNA (fine needle aspirate) the cells are examined under a microscope to determine what type of mass your pet may be having.

While uncommon, there are a few instances in which this aspirate may not provide the answer, so additional testing may be required.  If the mass does not provide enough cells for a sample, or if the cells look like they could come from several types of masses, then a biopsy may be required.  A biopsy involves anesthesia to remove a portion of the mass for testing, or in some cases removing the entire mass for submission. 

The results of the aspirate or biopsy will determine the next steps in treatment.  If the mass is benign, careful monitoring may be recommended to ensure that the mass does not grow to a size that it becomes a problem.  If the mass is malignant, the treatment will depend on the diagnosis, but may include surgery to remove the mass, chemotherapy, and/or radiation therapy.  Your veterinarian may recommend consulting with an oncologist to fully discuss the treatment options and the prognosis associated with treatment. 

If your dog has a lump or mass that you have noticed, speak with your veterinarian about having it sampled.  The testing can then determine what needs to be done next for treatment (if required). If you have questions about a mass or the sampling process, contact us at University Veterinary Hospital at 318-797-5522. 

If your dog has had a skin mass removed and you would like to discuss the diagnosis with our oncologist, Dr. Beck, you may also call us at the number above.

We look forward to helping you and your pet! 

Dr. Amanda Beck – The regions only pet cancer doctor!