Lexis and Westlaw both collect cases by subject matter; in either, navigate first to the Practice Area tab, then select Patent (Lexis) or Intellectual Property (Westlaw), and then scroll to Cases.
The following is a non-comprehensive list of a few additional, patent-specific sources for case law.
Chisum on Patents
For information on researching case law, see Georgetown Law Library's Case Law Research Guide or the Case Law Research Tutorial.
In addition to the above, a variety of patent-related administrative materials are available in collections on Lexis, Westlaw, and Bloomberg Law at the following locations:
For more on administrative legal research, generally, refer to our Administrative Law Research Guide or Administrative Law Tutorial.