Hamartoma in a goldfish

This fish developed a large irregular mass at the top of the opening to the gill cavity. It had become enormous and was causing problems with its swimming. The fish was given an anaesthetic and removed from the water for examination and successful surgical removal. There was no regrowth of the mass, which laboratory tests suggested was a hamartoma. These are uncommon and generally considered as non-cancerous abnormal growths.

Hamartoma 1
Hamartoma 1

This large tissue mass had become enormous in size and was causing problems with swimming

Hamartoma 2
Hamartoma 2

An anaesthetic was used to remove the fish from the water and allow a detailed examination of the mass

Hamartoma 6
Hamartoma 6

An electron microscope was used to examine some structures inside the cells of the tissue © Cefas

Hamartoma 1
Hamartoma 1

This large tissue mass had become enormous in size and was causing problems with swimming

1/7