Brief Answer:
possible neuro-muscular weakness..

Detailed Answer:
Hello dear , Welcome to HCM..

I've gone through your query and understand your concern..

Now Thymus tumor at this age is mostly related to Myesthenia Garvis..so please let me know if he's already diagnosed so ?

Is he on any particular medications like Pyridostigmine / Neostigmine ?

Yes sudden onset swallowing difficulty can result in to choking which is a life-threatening emergency so it's good that he was taken to the ICU as after complete monitoring there may be need to put put him on elective mechanical ventilatory support..

The swallowing difficulty as well as suffocation in this case , can be explained with sudden onset neuro-muscular weakness(if there was no other medical ailments which might have complicated the ongoing disease process).. there are certain chemicals present in between the nerve-muscle junction, which if get inhibited or blocked can not transmit nerve impulses , causing variety of symptoms from swallowing difficulty, drooling of saliva from mouth, slurring of speech, suffocation and even temporary to permanent paralysis(if not attended immediately)..

I hope now you can understand the reason as I've simplified the whole process briefly for your understanding..

So please let me know if you have any further doubts in this regard.. I'll be glad to clarify..

Take Care
Regards

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