Decalcification biopsy?

Hi vets. My dog recently got his toe amputated and sent away for biopsy. I asked today at his 10 day appointment if there was any update and she said it is having decalcification done and may take another 14 days. Is this a normal part of doing a biopsy or would there be a reason for this as they originally told me 7-10 days for results Thanks😊

Hello and thank you for persevering with this interesting question that I've never been asked before!    So... when we take a biopsy, the sample will often be soaked in fixative (to stop the cells 'going off') and sent to a lab, who will then use a machine called a microtome to slice up the sample.  The slices have to be incredibly thin - no more than a few cells thick - to make a good microscope slide, through which light can pass.   This requires extremely delicate equipment.  Unfortunately, some samples have deposits of some mineralised 'grit' in them, which the delicate 'slicing' technology can't handle.  Its probably like trying to cut slices of ham of a perfect thickness with a perfectly sharp knife, when the ham has bones embedded at unknown intervals.  When we're calving ham, it doesnt really matter if the slices are imperfect, but with tissues at this thickness, the lab will want to break down that mineral, in order to be able to cut the sample precisely.  Its a request I've had several times over my careeer.  Some of those samples have turned out to be cancerous - because cancers do often have calcium desposits within them.  However, that's not always the case; mineral deposits also form in the tissues for other reasons eg an excess of mineral in the body, or kidney or bladder stones.

A fuller list of possibilities might include:  anything with a bone, or fragment of bone, in.  Cancers.  Calcium deposits caused by cell death (necrosis) eg in the centre of an abscess.  Deposits in the walls of blood vessels.  We would be interested to know what is found, should you feel like sharing.

Should your vet have pre-empted the need for this?  I suppose it depends whether they expected the bone to be involved, or whether they had experienced these requests with previous cases / knew how the lab were likely to work.  Most samples do come back in a few days, so it's easy to assume that as a default and be taken by surprise to get a request for extra time for decalcification, especially if it's a soft-looking lump.  It's happened to me.

Ahh that makes sence thank you! Google wasnt much help and the vet said they have never heard of them doing this! He had a curved, fast growing nail which they at first removed. They said they found a small cyst like lump when removing the nail and ithe nail shouldnt grow back but if it did then best to get it amputated. So this is whats happened so we got it sent for biopsy as they said possible cancer. Just eager to know the results and wasnt sure if the extra time and this process was bad news! Happy to keep you updated 😊  

Best of luck