Bones, but no moans or stones

Case Identification

Case ID Number
Benign or Malignant

Clinical case information

Case presentation

A 58 year old woman has multiple lesions in multiple bones. She complains of "achy bones". She is weak, and has been confused and forgetful recently.

Laboratory results:
A CBC shows anemia.
Special Features of this Case:
What is the diagnosis? Why is the patient confused? What is the cause of the renal failure?