Crystals in body fluids
This article deals with crystals in body fluids.
Crystals
Joint crystals
Types:[1]
- Gout = needle-shaped, negatively birefringent, yellow when aligned.
- Pseudogout = rhomboid-shaped, positively birefringent, blue when aligned.
Notes:
- Pseudogout also known as CPPD = calcium pyrophosphate dehydrogenase.
- Memory device: ABC+ = aligned blue is calcium & cuboid - positively birefringent.
Images:
- Crystals - schematic (stpetes.org) from Microscopic Examination for Crystals in Synovial Fluid (stpetes.org).
- Blue rhomboid CPPD crystals (med.utah.edu).
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Urine crystals
Types - morphology:
- Envelope shape (calcium oxalate).
- Diamond shape (uric acid).
- Coffin-lid shape (struvite).
- Hexagonal shape (cysteine).
Notes:
- Memory devices:
- Diamonds are see-through; ergo, uric acid stones not seen on KUB.
- Calcium oxalate = envelope, uric acid = diamond.
- Uric acid crystals: usually dissolve in formalin... but do not dissolve in alcohol.[2]
- Calcium oxalate crystals are seen in the context of ethylene glycol poisoning.[3]
Diseases
Gout
General
- Classically big toe.
Gross/radiology
- Radiologically may mimic anconeus epitrochlearis muscle.[4]
Microscopic
Features:[5]
- Tophi (advanced)
- Aggregates of urate crystals.
- Reactive granulomatous inflammation.
- Fibrotic synovium.
Images:
- Gouty tophus - A. xray, B. Diff-Quick, C. Pap smear, D. polarized light, E. H&E (archivesofpathology.org).
- Gouty tophus - low mag. (WC).
- Gouty tophus - high mag. (WC).
Pseudogout
- AKA calcium pyrophosphate dehydrogenase, abbreviated CPPD.
General
- Classically found in the knee.
Microscopic
Features:
- Crystals with a rhomboid-shape.
- Positively birefringent, blue when aligned.
Notes:
- Memory device: ABC+ = aligned blue is calcium & cuboid - positively birefringent.
See also
References
- ↑ TN05 RH6
- ↑ WG. 8 January 2010.
- ↑ Saukko, Pekka; Knight, Bernard (2004). Knight's Forensic Pathology (3rd ed.). A Hodder Arnold Publication. pp. 589. ISBN 978-0340760444.
- ↑ URL: http://radiology.casereports.net/index.php/rcr/article/viewArticle/57/213. Accessed on: 7 August 2011.
- ↑ URL: http://pathologyoutlines.com/joints.html#gout. Accessed on: 5 August 2011.