Difference between revisions of "Tophus"
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==Preparation== | ==Preparation== | ||
| − | A tophus specimen should be sent '''dry''' to the pathology department, and '''not''' be put in formalin.<ref group=notes>Formalin dissolves the crystals.</ref> A touch prep can be done initially, and at least if urate crystals | + | A tophus specimen should be sent '''dry''' to the pathology department, and '''not''' be put in formalin.<ref group=notes name=dissolves>Formalin dissolves the crystals.</ref> A touch prep can be done initially, and at least if urate crystals are not initially detected, the specimen is submitted in 100% alcohol for microscopy evaluation.<ref group=notes name=dissolves/> |
==Microscopy evaluation== | ==Microscopy evaluation== | ||
| − | + | On a touch prep, look for needle-shaped crystals of urate. On polarized light, these will have negative birefriengence. | |
<gallery mode=packed> | <gallery mode=packed> | ||
File:Light microscopy of a touch preparation of a gout tophus, showing urate crystals.jpg|thumb|Light microscopy of a touch preparation of a gout tophus, showing needle shaped crystals | File:Light microscopy of a touch preparation of a gout tophus, showing urate crystals.jpg|thumb|Light microscopy of a touch preparation of a gout tophus, showing needle shaped crystals | ||
Revision as of 13:24, 28 September 2020
Author:
Mikael Häggström [note 1]
Preparation
A tophus specimen should be sent dry to the pathology department, and not be put in formalin.[notes 1] A touch prep can be done initially, and at least if urate crystals are not initially detected, the specimen is submitted in 100% alcohol for microscopy evaluation.[notes 1]
Microscopy evaluation
On a touch prep, look for needle-shaped crystals of urate. On polarized light, these will have negative birefriengence.
Light microscopy of a touch preparation of a gout tophus, showing needle shaped crystals
Uric acid crystals in polarized light, showing negative birefringence, with yellow color when aligned parallel to the axis of the red compensator, and blue when aligned perpendicularly to it.[1]
Notes
- ↑ For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Patholines:Authorship for details.
Main page
References
- ↑ Bruce M Rothschild. Gout and Pseudogout Workup. Medscape. Updated: Jun 30, 2020
Image sources
