It is an exclamation expressing astonishment or unexpectedness.
Here are some variations and contexts where it might be used:
* ¡Qué sorpresa! (with an exclamation mark) - This is the most common and direct way to express surprise.
* ¡Qué sorpresa, verte aquí! - "What a surprise, to see you here!" - This is used when you unexpectedly encounter someone.
* ¡Qué sorpresa, me has hecho un regalo! - "What a surprise, you gave me a gift!" - This is used when someone has given you something unexpected.
It's a versatile phrase used in various situations to express surprise and delight.