Is it possible to get lymphoma from one chest ct scan?

Not sure what you...: ...mean but if you are asking if the radiation exposure from just one CT scan is enough to cause cancer, I think that would be exceedingly unlikely. There are inherited traits that lead to increased cancer risk with radiation exposure but even then it would be a very rare occurrence. Cannot say it is impossible, though. That is why scans have to be ordered when truly necessary, not capriciously.