Misdiagnosis of a chylous cyst as chest wall gouty tophus: A case of true pseudogout

Abstract

A patient referred to us for recurrent chest wall gouty tophus, but who was determined to actually have a chylous cyst, is described herein. Chylous cysts of the neck or chest wall can be caused by thoracic duct injury. Chyle contains 4-40 gm/liter of lipids, mostly triglycerides, and these can form birefringent crystals upon drying, leading to a false diagnosis of gout. © 2007, American College of Rheumatology.