Correspondence

Medical Mystery: Arthritis — The Answer

N Engl J Med 2006; 355:421-422July 27, 2006

Article

To the Editor:

The medical mystery in the June 1 issue1 involved a 51-year-old woman with a 15-year history of rheumatoid arthritis, who presented with swelling and a loss of function of the right shoulder. Microscopy of the synovial fluid drawn from this shoulder showed geometric plates with notched corners, pathognomonic of monohydrate cholesterol crystals (Figure 1AFigure 1Cholesterol Crystals in Synovial Fluid.). Analysis of the synovial fluid revealed a leukocyte count of 2100 per cubic millimeter, a total cholesterol level of 7.8 g per liter, a low-density lipoprotein cholesterol level of 6.1 g per liter, a high-density lipoprotein cholesterol level of 1.7 g per liter, and a triglyceride level of 0.83 g per liter. The plasma lipid profile was normal.

Cholesterol crystals are found only sporadically in the synovial fluid of patients with rheumatoid arthritis. Such crystals may appear in two morphologic forms: large, flat, rectangular plates that are negatively birefringent (doubly refracting) with notched corners, ranging from 8 to 100 μm long and consisting of monohydrate cholesterol, or rod-shaped, helical birefringent crystals, ranging from 2 to 20 μm long and consisting of anhydrate cholesterol. Since these large cholesterol plates are difficult to clear, they are thought to play a role in the perpetuation of the arthritis.

Tim L. Jansen, M.D., Ph.D.
Anneke Spoorenberg, M.D., Ph.D.
Medisch Centrum Leeuwarden, 8934 AD Leeuwarden, the Netherlands

1 References

1. 1

   Jansen TL, Spoorenberg A. A medical mystery -- arthritis. N Engl J Med 2006;354:2375-2375
   Full Text | Web of Science | Medline

Citing Articles (1)

Citing Articles

1. 1

   Alexander P. Rozin, Kohava Toledano, Doron Markovits, Alexandra Balbir-Gurman. (2010) Imaging mystery. Rheumatology International 30:10, 1409-1410
   CrossRef