Finding a lump on your pet isn't necessarily a cause for alarm and even if it's a form of cancer, there are likely multiple treatment pathways available.
Let's delve into the process of identifying what the lump is and what potential treatment routes exist.
Understanding the terminology
The language surrounding such conditions can often be intricate and you might encounter terms like lump, mass, growth, tumour, neoplasia or cancer used interchangeably. In general, 'lump' and 'mass' are used descriptively when we're still unsure about the nature of the issue.
A lump could be a fluid filled cyst, an abscess, a result of inflammation, for instance, around a hair follicle or foreign object like a thorn and not necessarily a growth. When we talk about a growth, tumour or mass, we're referring to some form of cancer, which takes place when the standard mechanism controlling cell growth, division and repair goes amiss. Nevertheless, a growth, tumour, or mass can be harmless, implying it is non-aggressive and does not spread elsewhere in the body, or malignant, which means it's likely to spread to other parts of the body or invade adjacent structures.
What’s the first step? - Investigation
The initial step for a vet is to evaluate the lump. We might investigate the following:
- Does the lump feel hard or soft?
- Does it cause discomfort?
- Can it move freely within the skin layer or is it affixed to deeper structures?
- Has there been hair loss over the lump (if it's situated on a hairy area of skin), and has it turned red, tender or developed ulcers?
At times, it may seem evident that the mass is a fatty lump, a wart or a cystic lesion, but some lumps may be encapsulated by fat or resemble other types of masses. To definitively identify the lump, sampling should be undertaken.
What makes sampling so crucial?
The objective of sampling is to ascertain the lump's nature, which subsequently informs the vet's treatment strategy. We're seeking answers to the following questions when taking a sample:
- Is it an inflammatory response or a tumour?
- If it's a tumour, what kind is it and is it benign or malignant?
- Is ongoing observation suitable?
We then come up with a plan to treat your pet - can the lump be locally excised (removed with a minimal amount of surrounding normal tissue), or does it necessitate more complex surgical procedures to remove more significant portions of surrounding tissue to avoid relapse?
What kind of sample will my vet collect?
The type of sample to be taken relies on numerous factors, such as the lump's location and size, your pet's disposition, the appropriateness for sedation or anaesthesia and associated costs.
We'll discuss these factors with you, but please feel free to reach out to us if you have any uncertainties, questions or worries.
Generally, there are two sampling methods. The first one is called cytology, carried out via a fine needle aspirate (FNA). A small needle, similar to one used for blood samples, is inserted into the lump. A syringe is used to create suction, after which the needle is withdrawn, and the contents from the needle hub are spread onto a microscope slide. The slide is then evaluated either in-house or sent to an external laboratory for a specialist pathologist's review. This technique is minimally invasive and can typically be executed during your consultation or scheduled for a more extended consultation.
Often, sedation or anaesthesia is not required if your pet is cooperative. This method is relatively cost-effective compared to a biopsy, and results are typically available within a few days. However, as this method only collects a few cells and not a larger tissue sample, there might be instances where we don't receive a definitive answer, leading us to consider 'plan b' (a biopsy).
Considering a biopsy
The other method is to conduct a biopsy. This involves extracting a larger piece of tissue to send to a lab for histopathological examination. As it's a surgical procedure, it entails admitting your pet for the day to perform the process under general anaesthesia. The advantage is that it provides the lab with more tissue to analyse, thus reducing the likelihood of inconclusive results. However, it does involve anaesthesia, making it more costly. A biopsy usually doesn't completely remove the lump, indicating a possible need for a second surgery.
Could we simply remove the mass?
The best practice for a vet is to encourage preliminary lump sampling. This enables the vet to understand what the lump constitutes, thus allowing for the choice of the most effective treatment and determining the extent of normal tissue to be eliminated. This step mitigates uncertainty and reduces the risks of recurrence and complications. However, there may be instances where compromises are necessary, and we recommend discussing these alternatives with us to develop a customized treatment plan that best accommodates both you and your pet.
In certain cases, if the mass is minuscule and situated in a region with ample 'extra' skin, a biopsy might lead to its total removal. Yet there could be situations where the histopathology result may suggest that the mass has infiltrated the surrounding tissues, necessitating additional surgery to remove more skin.
When in doubt, reach out to us
Determining the nature of the lump through examination alone is challenging due to the variety of lump types. Sampling provides us with a better understanding of the lump's nature and its likely behaviour, such as potential growth or spreading tendencies. This knowledge helps us decide whether to dismiss concerns about the lump or if a treatment plan is needed.
Having appropriate pet insurance is essential to address unexpected situations such as discovering a lump on your pet. More advice on pet insurance can be found here.
If you detect a lump on your pet, please contact your local Alder Vets in Guildford to book an appointment.