I apologize for not having the ID of the shrub/small tree growing in SW Washington State, but this stem damage is showing up now. I don't know if it's insect related. I can tear apart the stem and not find any critter. Virus? Bacterial? Just thought I'd start with this forum.
Likely the best place to ask would be the Pest and Disease Forum
http://davesgarden.com/community/forums/f/pad/all/
They will know the best questions to ask to lead up to an answer for you. :)
Try the Master Gardeners at your local Cooperative Extension office: http://mastergardener.wsu.edu/program/county/
I am a master gardener and work in a Virginia Cooperative Extension Office. We operate a Help Desk manned by MGs and any pest or disease problem on samples we can't diagnose in-house are sent to the labs at Virginia Tech University for analysis ~ free to the client. Extension Offices are a fantastic resource that are generally under-utilized because folks just don't know about them.
The 'shepherd's crook' appearance of the terminal growth is typical of fire blight (caused by a bacterium), but affected tissues usually become much darker than seen in this image - see http://f.tqn.com/y/forestry/1/W/7/p/fire_blight.jpg and https://www.ppdl.purdue.edu/PPDL/images/fire-blight1.jpg
