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Pet Doc
Pet Doc, Veterinarian
Category: Veterinary
Satisfied Customers: 7457
Experience:  Veterinarian - BVSc
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My 10yr old male Boxer has a lump on the inside of his rear

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My 10yr old male Boxer has a lump on the inside of his rear leg just above his ankle joint. The lump is approximately the size of an egg, is soft and moveable. It grew quite quickly. He's not limping and it doesn't seem to have any effect on his health... any ideas???
Hi there,

Thanks for your question regarding your 10 year old Boxer boy who has a lump that has developed on the inside of his rear leg near his ankle joint. There are a number of things this mass could be, and it is a bit of a worry this seems to be growing so quickly. This could potentially be anything from a lipoma (benign, fatty lump), to a benign cystic mass, another benign mass like a basal cell tumour, or potentially something malignant like a melanoma or mast cell tumour.

Whatever the case, I really would encourage you to follow up on this with your Vet this week if possible. The best next step here is to get a sample from this mass using a needle. This is a procedure called an FNA or Fine Needle Aspirate which is a quick, easy and painless procedure that can be carried out with no anaesthetic and Sydney completely awake! A needle is inserted in to the lump, a syringe is used to 'aspirate' cells in to the needle hub, and then these are then placed on to a micrscope slide and sent to a pathologist for analysis. Many times a diagnosis can be gained via this FNA procedure. From this diagnosis your Vet will be able to tell you what needs to be done next, whether that is monitor the mass or remove it under a full general anaesthetic.

Do try and follow up on this with your Vet this week if you can - as it sounds like this mass is growing quite quickly and it is better to be proactive with these sort of lumps.

Best of luck with Sydney and let me know how you get on.

Kind Regards,

Dr Edwards
Customer: replied 4 years ago.

Thank you... Will do...


It may be some less than reliable advise I've received, but I was told if it was something sinister like a melanoma or mast cell tumour there'd be more than one on his body... I'm thinking this may not be correct...

Hi Di,

No - that is definitely not the case. They can have just one solitary mass in the case of both melanoma AND mast cell tumours. Definitely follow up on this mass and have an FNA performed to get a diagnosis from this mass won't you.

Let me know how you get on.

Kind Regards,

Dr E
Customer: replied 4 years ago.

Certainly will... Thank you again

No problem Di :-)
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