Difference between revisions of "Tophus"
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==Microscopy evaluation== | ==Microscopy evaluation== | ||
| + | Evaluation of a fresh tophus can start as a touch prep to 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:Uric acid crystals in polarized light.png|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.<ref>{{cite web|url=https://emedicine.medscape.com/article/329958-workup|title=Gout and Pseudogout Workup|author=Bruce M Rothschild|website=Medscape}} Updated: Jun 30, 2020</ref> | File:Uric acid crystals in polarized light.png|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.<ref>{{cite web|url=https://emedicine.medscape.com/article/329958-workup|title=Gout and Pseudogout Workup|author=Bruce M Rothschild|website=Medscape}} Updated: Jun 30, 2020</ref> | ||
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Revision as of 13:22, 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 remain suspected, the specimen is submitted in 100% alcohol for microscopy evaluation.
Microscopy evaluation
Evaluation of a fresh tophus can start as a touch prep to 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
- ↑ Formalin dissolves the crystals.
- ↑ 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
