Why is there no scheduled cached thread pool provided by the Java Executors class?

Executors provides newCachedThreadPool() and newScheduledThreadPool(), but not newCachedScheduledThreadPool(), what gives here? I have an application that receives bursty messages and needs to schedule a fairly lengthy processing step after a fixed delay for each. The time constraints aren't super tight, but I would prefer to have more threads created on the fly if I exceed the pool size and then have them trimmed back during periods of inactivity. Is there something I've missed in the concurrent library, or do I need to write my own?