20 years old can still gain height?

Normally you stop gaining height somewhere between 18 and 21. Some do earlier others later. Some people however have a brain tumour causing their body to grow and grow for decades, which mostly leads into reaching insane heights such as 2.30, 2.40, 2.50 etc etc... In my country the height gain is being registered for a few years so that an estimation of the final height can be made as well as steps in between and compared to the actual situation, it says something about your health.