What causes soft movable lump in hand?
It looks like Ganglion
As per your description, it looks like a Ganglion.
It occurs in relation to the tendons.
There is no medical treatment for this condition.
When the tendon is free,it moves.When the tendon is made taut,the movement is restricted.
The movement of the swelling is not of much concern.
Nothing to worry.
You can get it removed surgically after your trip or still later date.
Hope I answered your query. If you have any questions, I will clarify further.
Wish you good health.