Crystals in body fluids

From Libre Pathology
(Redirected from Crystals in fluids)
Jump to navigation Jump to search
Crystals (gout) and blood cells in polarized light. (WC/Gabriel Caponetti)
Crystals in urine. (WC)

This article deals with crystals in body fluids.


Joint crystals


  • Gout = needle-shaped, negatively birefringent, yellow when aligned.
  • Pseudogout = rhomboid-shaped, positively birefringent, blue when aligned.


  • Pseudogout also known as CPPD = calcium pyrophosphate dehydrogenase.
  • Memory device: ABC+ = aligned blue is calcium & cuboid - positively birefringent.

Urine crystals

Types - morphology:

  • Envelope shape (calcium oxalate).
  • Diamond shape (uric acid).
  • Coffin-lid shape (struvite).
  • Hexagonal shape (cysteine).


  • 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][3]
  • Calcium oxalate crystals are seen in the context of ethylene glycol poisoning.[4]




Sign out

Urine cytology

Negative for malignant cells.
Mainly squamous cells present. Cuboidal/rhomboidal crystals present.




  • AKA Calcium pyrophosphate dihydrate deposition disease,[5] abbreviated CPPD.

See also


  1. Yeung, J.C.; Leonard, Blair J. N. (2005). The Toronto Notes 2005 - Review for the MCCQE and Comprehensive Medical Reference (2005 ed.). The Toronto Notes Inc. for Medical Students Inc.. pp. RH6. ISBN 978-0968592854.
  2. Geddie, W. 8 January 2010.
  3. Shidham, V.; Chivukula, M.; Basir, Z.; Shidham, G. (Aug 2001). "Evaluation of crystals in formalin-fixed, paraffin-embedded tissue sections for the differential diagnosis of pseudogout, gout, and tumoral calcinosis.". Mod Pathol 14 (8): 806-10. doi:10.1038/modpathol.3880394. PMID 11504841.
  4. Saukko, Pekka; Knight, Bernard (2004). Knight's Forensic Pathology (3rd ed.). A Hodder Arnold Publication. pp. 589. ISBN 978-0340760444.
  5. URL: Accessed on: 28 October 2011.

External links