William H Wildgoose MRCVS
Pet fish vet
Spindle cell tumours in goldfish
These are the most common skin tumours in goldfish and are so called because of the microscopic shape of the cells. They often start as a small orange patch on the skin, that increases in size over months or years to form a distinct mass. It is not uncommon to find several on the same fish, all at various stages of development. Many get larger, and some become so large that they require surgical removal. Others stay the same size for years, while a few will disappear. No medicines added to the water will change the outcome

This is a typical spindle cell tumour in a fancy goldfish, which had grown enormously on its back and was now affecting its buoyancy

It is rarely possible to remove the whole tumour, but in this case, it had a small attachment which was cut flush with the skin surface and cauterised under anaesthetic

The general category of spindle cell tumours includes fibromas and fibrosarcomas, peripheral nerve sheath tumours (neurofibromas, schwannomas, etc) and pigment cell tumours (melanoma, erythrophoroma, xanthophoroma, etc). These require electron microscopy, immunohistochemistry and pigment analysis to differentiate them more accurately.

This is a typical spindle cell tumour in a fancy goldfish, which had grown enormously on its back and was now affecting its buoyancy