Help identifying a white cyst looking thing on sailfin

[Michael E.]

Hi everyone,

need a little help identifying this. It was on the tail of my sail fin, which I was able to get off during a freshwater dip. My fish are all qt’d, but I must have missed something. The sailfin was in my DT.

 

[Jay Hemdal Verified Community Expert]

What did the lesion look like visually?
Where these moving at all?
Did it fall off during the dip or did it get scraped off?

Jay

 

[Michael E.]

It looks like a little white cyst almost. Maybe a quarter the size of a grain of rice? It was scraped off, but seemed to loosen during the dip.

 

[Michael E.]

Oh...and no I didn’t notice any movement

 

[Michael E.]

Here’s the best picture I could get. That growth did come back

 

[Jay Hemdal Verified Community Expert]

That is very likely Lymphocytis, the round things in the microscope are gigantisized cells that the virus causes. If so, it may get worse before it gets better, but no treatment is needed and it will go away in around 6 weeks.
Jay

 

[Michael E.]

That is very likely Lymphocytis, the round things in the microscope are gigantisized cells that the virus causes. If so, it may get worse before it gets better, but no treatment is needed and it will go away in around 6 weeks.
Jay

I agree. Figured a second pair of eyes would be helpful. Thank you!