What We Do When There Are Tumors On the Inside and On the Outside

Patrick Mahaney, VMD, CVA, CVJ
By Patrick Mahaney, VMD, CVA, CVJ on Sep. 25, 2015

Before Cardiff became sick with his cancer reoccurrence, a plan to address several superficial skin masses that had gradually developed on the surface of Cardiff’s skin was in the works.

Despite the fact that his teeth appeared quite clean from my nightly brushing endeavors, my plan was to anesthetize him for a dental cleaning and remove the masses for biopsy while he was under. When an abdominal ultrasound revealed another mass-like lesion on a loop of small intestine, this plan was knocked down a few notches on the priority scale.

From their appearance on the skin’s surface, the majority of Cardiff’s masses weren’t clinically concerning. Most were pink, raised, had a lobulated shape, and appeared like a pink piece of cauliflower. I suspected they were sebaceous adenomas, which are benign tumors of oil-producing glands.

Cardiff’s masses had been present for months, but the subtle increases in size and changes in shape along with the dark pigmentation of two of the masses had me somewhat concerned that cancerous cells with malignant characteristics were the underlying causes.

Yet, any mass could have a more sinister cellular makeup than what the outward appearance lends the veterinarian to believe. Therefore, it's crucial to appropriately monitor all skin masses by measuring their size, describing their physical characteristics, and watching for changes. Additionally, any surgically removed masses or other bodily tissues should always be sent off for biopsy.

I’m a big advocate of Dr. Susan Ettinger’s “See Something, Do Something (Why Wait? Aspirate)” campaign and apply the principles to my patients. Basically, “See Something” means that “when a skin mass is the size of a pea or larger, or has been present for 1 month” we then must “Do Something” by taking the steps to “aspirate or biopsy, and treat.”

If you’re not familiar with this concept, to aspirate is to perform a fine needle aspirate (FNA), by which a needle is inserted into a mass, the plunger of the attached syringe is pulled back to remove cells (or fluid), and the cells are then applied to a glass slide for cytology (microscopic evaluation of the cells).

Although FNA and cytology are helpful, only a small portion of cells potentially existing in a mass may be collected. It’s akin to having only one spoon of ice cream as compared to the entire pint.

Biopsy involves attaining a larger tissue sample so that the architecture of the cells can be visualized under the microscope and a much more definitive picture of disease can be achieved. Biopsy may be an evaluation of an entire mass-like lesion (excisional) or it can be performed on a chunk of tissue (incisional). Biopsy is the metaphorical pint of ice cream that yields a greater degree of satisfaction by increasing the likelihood that a definitive diagnosis will be achieved.

In Cardiff's case, his skin lesions have minimally changed since they appeared at varying times over several months. All are less than the size of a pea, but as they’ve been present for more than one month I’m guilty for not having done an FNA or biopsy sooner. All of the sites were too small for me to realistically achieve an FNA for cytology, so I was planning on moving right to the biopsy stage via surgical excision.

The original plan was to remove Cardiff’s masses at the same time as his intestinal tumor and bladder stones, but concerns arose for his safety since his blood pressure was trending below the normal range.

Fortunately, Dr. Justin Greco, the veterinary surgeon, was calling the shots and prioritized Cardiff’s overall health in concluding that the skin mass removals would have to wait. Instead, I would give Cardiff two weeks for his abdominal surgery sites to heal, and then sedate him to remove any skin masses I was able to locate.

So, the plan for an additional surgery was set and this time I would be Cardiff’s surgeon. Having neutered Cardiff as a younger dog and having assisted on his first abdominal surgery in 2013 to remove an intestinal tumor (see How a Vet Diagnoses and Treats Cancer in His Own Dog), I have an inherent level of comfort functioning as my dog's surgeon in this capacity. Removing skin masses is something I regularly do. However, opening up the abdomen to remove the mass (and the scar tissue from the 2013 procedure) and the bladder stones is better suited to a more skilled surgeon than myself, like Dr. Greco.

I sought the skills of my trusty technician Erin Zimmer from Veterinary Cancer Group to oversee Cardiff’s sedation. She closely monitored Cardiff’s respiratory and heart rate, blood pressure (normally maintained), and pulse oximeter (blood oxygen saturation) so I could focus on his surgery.

Fortunately, the removal of Cardiff’s skin masses was fairly straightforward. In total, I removed nine masses in locations ranging from his muzzle to his groin to his left carpus (wrist). An eight millimeter punch biopsy instrument was sufficient to cut out most of his masses, but I also needed a scalpel to attain larger margins around some masses that had a diameter greater than a few millimeters.

The sites were closed with surgical staples or sutures. In locations of thicker skin, staples permit sufficient closure and are very quick to place. In body parts having thinner skin, such as further down on Cardiff’s limbs, I used individual sutures to create a simple interrupted closure.

Cardiff had a routine recovery from his sedation and entered another 14 day convalescent period to let his skin heal before for he would start chemotherapy. Some of his biopsy results are rather eye opening, so I’ll get into the details in my next column.

Cardiff and I thank you for reading. Feel free to share this column, along with my previous columns on the topic with your family, friends, or with owners who are going through the cancer treatment process with their pets. You’ll find some of my previous columns in the “Related” links below.

cancer surgery, tumor surgery

Cardiff under sedation and being prepped for multiple skin mass removals.

cancer surgery, tumor surgery, skin tumors on dog

Cardiff recovered from the sedation for his skin mass removals.

Dr. Patrick Mahaney


When Cancer That Was Successfully Treated Reoccurs in a Dog

What Are the Signs of Cancer Reoccurence in a Dog, and How is it Confirmed?

Surgical Treatment of Canine T-Cell Lymphoma in a Dog

Patrick Mahaney, VMD, CVA, CVJ


Patrick Mahaney, VMD, CVA, CVJ


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