Q. My 5-year-old Labrador Retriever has had a large lump beneath the skin on his chest. This lump has more than doubled in size. Recently we found another small lump on his side. Neither seems to bother him even though they are very hard. My veterinarian says they are fatty deposits and nothing to worry about. A friend of mine had a Golden Retriever with several of these lumps, which their veterinarian also described as fatty deposits. That dog lived only 8 years and died suddenly after a week-long illness. Should I get a second opinion?
Q. My 8-year-old Border Collie/Labrador mix, Bonnie, was recently diagnosed with mastocytoma (mast cell tumor) after having two tumors surgically removed. One tumor was near her eye, the other under the skin on her abdomen. Bonnie has not shown any signs of discomfort other than is natural after surgery. My veterinarian recommended she be put on aggressive chemotherapy treatment. I am reluctant to put my dog through that. If you have more information, please let me know.
A. I chose to answer these two letters together to highlight the importance of correctly identifying lumps and bumps. Unfortunately, many veterinarians trust their experience and intuition when diagnosing skin and subcutaneous (beneath the skin) masses. While they are often correct, mistakes are sometimes made.
Veterinarians have two options to learn more about a lump:
- Extract cells from the lump with a needle and syringe and evaluate them under a microscope.
- Remove lumps surgically and examine them. If they still cannot be diagnosed, submit them for microscope examination.
Generally, I recommend quick surgical removal of all lumps to allow diagnosis and treatment in one procedure. Some normal tissue is taken with the lump and evaluated by a pathologist to determine if the cancer was completely removed.
Removing lumps while they’re as small as possible reduces the chance of malignant tumors spreading and minimizes postoperative discomfort and surgical cost and risk. It also provides more healing time.
Mast cell tumor or mastocytoma, as diagnosed in Bonnie’s case, is common. Surgical removal is usually the best treatment. If the tumor has not spread to the lymph nodes or the bloodstream, removal may be a cure. Moreover, complete removal – with no evidence of spreading – can avoid chemotherapy.
Ask your veterinarian for a consultation with a veterinary oncologist if you are not comfortable with a cancer diagnosis or rendered treatment.