1. A painless, swollen finger (for 20 years)
Dr Anton Alexandroff, PhD, Nigel Kirkham, MD, Neena Nayak, MRCP 
The Lancet 
Volume 371, Issue 9618, (March 2008)
DOI: /S (08)
Copyright © 2008 Elsevier Ltd Terms and Conditions

2. Figure
Gout
(A) The swollen interphalangeal joint. (B) Negatively birefringent crystals. Birefringence is double refraction, and occurs with materials that are anisotropic: they scatter light unevenly. In pseudogout, joints contain positively birefringent crystals of calcium pyrophosphate dihydrate.
The Lancet  , DOI: ( /S (08) )
Copyright © 2008 Elsevier Ltd Terms and Conditions