This is a large form sport variegated Monstera deliciosa. Its leaves will grow much larger than a Monstera deliciosa var borsigiana and its internodes are much shorter - If you are familiar with variegated Monstera, it has the same growth pattern as a ‘Thai Constellation.’
This plant is likely sport variegated - the amount of actual variegation that the plant is presenting is very feint - but it is present on all the leaves and stems. It is possible with more light and time that you will get more variegation. It's also possible that you won't!
I've included pictures of the stem and petiole.
It is MUCH less common to find a large form variegated Monstera than it is to find a small form variegated Monstera. Even though the amount of variegation on this plant is feint, the fact that it is present on all the leaves and stem means this is a really special find, and I hope it goes home with someone who will truly love it!!