Weight loss, weakness and proteinuria

A 65-year-old woman presents to a doctor for the first time in 25 years, with a history of weight loss and weakness.

On examination, she is hypertensive and her extremities demonstrate pitting edema.

Urinalysis shows proteinuria. An abdominal fat pad tissue biopsy reveals deposits of amyloid, while further immunochemical staining demonstrates serum amyloid A proteins.