Part of our daily activity invariably involves checking out various lumps and bumps on our patients. By far they appear to be more common on dogs than cats, but both species can be afflicted with a wide range of skin tumors and lumps. It is important to note that tumor does not always equal cancer! This appears to be the primary concern or fear that owners have when presenting their pets to us for evaluation. It is often difficult to look at a tumor or lump and determine its true tissue type. There are papillomas, lipomas, mast cell tumors, epidermal inclusion cysts, sebaceous adenomas, and the list goes on from there. The diagnostics used to determine the type of mass and therefore the “best” treatment option is variable and to some extent dependent on the nature of the mass. We will often start with aspirates of tumors to try and obtain a representative sample of cells which guides us as to whether or not further treatment is necessary. They can often be done without any anesthesia and are minimally painful. 

Aspirates may yield a definitive answer as to what type of tumor we are dealing with, however there are some instances in which cytological samples may not reveal the true nature of the lump. In these cases, we may recommend a biopsy of the mass to then decide what type of tumor we are dealing with. If the tumor is fairly small and not near the face or head, we may be able to obtain our sample with a sedative and local anesthetic. Many however will require the use of a general anesthetic to get samples of tissues. Many owners will ask why the mass can’t simply be removed and this is an excellent question. It isn’t that a tumor “can’t” be removed entirely in one procedure, many times economic factors dictate that we do! It is more that by obtaining a representative sample of tissue, whether by aspirate or biopsy, we can better understand the type of tumor we are dealing with and so plan our surgery more effectively in order to minimize the likelihood of recurrence or plan for follow up care and or treatment if the mass should end up being cancerous or malignant. Finally, it is worth noting that it is better to proceed with biopsy/aspirate or tumor removal while a mass is small and relatively easily dealt with than to let it grow uncontrolled for longer periods of time. There is no magic cutoff or criteria by which we can decide when to proceed, but as a general rule it is better to deal with a small tumor than a large one! The attached pictures are of Cocoa, a Corgi with a little problem on the side of his face! Fortunately, despite its size, we were able to remove this growth without major complications or problems. His surgery incidentally was performed after an aspirate showed no significant indications of cancer.
Posted by Dr. Billeter