A 45 year old female presents to your clinic complaining of weakness. She has trouble getting out of a chair or reaching for books on high shelves. She cannot identify when it started, but the weakness has been getting worse over the last few months. The weakness is symmetric and associated with mild muscle tenderness. On exam, you do not find any signs of muscle atrophy. Instead, you note the following:
Challenge: What's your diagnosis?
First two images are in the public domain; last two images shown under fair use.