Content status, view different fields, different roles I want to know if there are any modules for the following situation:

User X of role A creates a case (special node type). If user Y logs on (of role B). He sees a case has been submit. He then can add pictures to the case (user X can't do this, he doesn't have the rights). Once that is done User X will see a the new node and can check out the pictures (but can't change them, or delete). And so on untill the case has the status closed.

I've looked at some modules for this and the Workflow module seems to lack what I want to do here.

I'm pretty sure people must have done something similar to this so that's why I'm asking.

Modules I know i'll have to know:

Views (to get my lists of a content type with a certain status)

Is this possible at all in Drupal? Worst case scenario is that I'll extend a node with my own entity and keep the node id, and programatically change the state of the node and let users add pictures. 

Thanks for reading!
If pictures should be part (field) of a case node type, use Field Permissions module to set separate permissions for different roles.

If pictures should be separate node type, use Entity reference module to reference parent case from picture node. On the case page you can add a Views block with pictures referencing this case with a button to add new picture.

In both cases you would need some custom code to support your particular workflow.