Does Your Pet Have Any Lumps or Bumps?

                        Over time with more research and education, veterinarians and pet owners have become better at caring for pets. As a result, our four–legged family members are living longer.  However, as pet longevity increases, so does a pet’s risk for cancer.       With this in mind, I thought I would review the tumors veterinarians diagnose most frequently in pets of any age, and on a daily basis.

            

                       Let’s begin with skin cancers since skin is the largest organ of the body and easy to investigate.  The most common skin tumor has to be the sebaceous adenoma, a benign (good) growth originating from the skin’s oil or “sebaceous glands.”  These tumors typically are small (1/4 to ½ inch), raised, pink, and bumpy.  Many pet owners refer to them as “warts” although they are not warts at all.   

                        Sebaceous adenomas, more likely to occur on small dogs, will grow anywhere on the body.  Because they are raised and irregular, they occasionally get abraded during scratching or grooming, then begin to ulcerate and bleed.  I usually recommend surgical removal, which is curative, if these tumors are bothersome to the patient, unsightly, or in bad locations (e.g. on the feet where the pet may lick constantly, or on eyelids and earflaps). 

                        Similar to sebaceous adenomas, sebaceous “cysts” are the result of plugged oil glands that allow sebum, the skin’s oil, to accumulate in a pocket in the skin. Since these cysts are within the skin, they will be only slightly raised and feel smooth and firm. Sebaceous cysts may get over-filled and inflamed, and sometimes even infected and painful. At this point, the cyst may rupture and drain, and antibiotics may be necessary.  Surgical removal is also curative for sebaceous cysts.

                        Lipomas, or benign fatty tumors under the superficial skin layer, are extremely common. These growths are abnormal, well-defined, round, clumps of fat that may be singular or multiple.  They occur anywhere on the body with the majority growing on the chest or abdominal areas in dogs.  Lipomas are readily diagnosed with a simple needle aspirate (biopsy) by your veterinarian.  This tumor is benign, but it may also get very large in its location.  I do not recommend “watching” lipomas grow, because grow they will…the largest lipoma I have seen was the size of a volley ball.

                        Histiocytoma (HCT) is the name given to a benign skin tumor most commonly diagnosed in young dogs, even and including puppies.  HCT’s tend to appear as flat, raised, round, plaque-like, ulcerated growths on the skin.   This is one tumor type that may actually regress and disappear without treatment.  Because of this phenomenon, your veterinarian may give this tumor an observation period before recommending surgical removal.

                         In humans, melanoma is considered a dreaded malignancy, but for pets, this skin tumor is usually benign.  Because melanomas in pets are typically pigmented black, they may be readily diagnosed with a needle aspirate. Once again, surgical removal of skin melanomas is curative.  However, melanomas occurring in and around pets’ mouths are usually malignant and require aggressive surgery and additional therapies.

                        Veterinarians dread diagnosing yet another class of tumors called mast cell tumors (MCT).  This tumor class is graded 1 to 3 on microscopic examination based on its malignancy potential.  Surgical removal with wide and deep margins is recommended for MCT’s.  Depending on biopsy description and the grade given to each MCT, further surgery and/or chemotherapy may be recommended.  MCT’s are “great foolers” and can have a variety of appearances varying from very small, smooth and innocent to large, ulcerated and angry.

                        Another kind of tumor diagnosed frequently by veterinarians is the soft tissue sarcoma (STS) group.  There are several tumors, including hemangiopericytomas and fibrosarcomas, that make up this group of malignant tumors originating from cells under the skin.  STS cancers are malignant as they are extremely difficult to completely remove with surgery, in spite of what appear to be well-defined tumor margins. As a result, additional therapy beyond surgical removal is often recommended for this tumor class. 

                        A pet that presents with enlargement of multiple, external lymph nodes will likely be diagnosed with lymphosarcoma (LSA).  This cancer often involves enlargement of internal lymph nodes, and sometimes the liver and spleen.  LSA is a commonly diagnosed cancer that is treatable.  Multiple chemotherapy protocols for LSA exist that pets seem to tolerate quite well.  Frequent monitoring of blood work will be recommended for LSA patients treated with chemotherapeutics.

                        Cancers in pets can be numerous and varied.  These are just some of the frequently diagnosed tumors visible on a pet’s exterior body.  Several other cancers can occur inside the body cavities and on pets’ bones (osteosarcoma) as well.  If you notice a growth on your pet’s body, or if your pet isn’t acting quite right, don’t procrastinate in seeking your veterinarian’s advice. Peace of mind could be just a needle aspirate away.

Author:  Dr. Bonnie Jones
Image courtesy of jscreationzs at FreeDigitalPhotos.net