Identification of crystals in joint fluids.

The inflammatory process present in synovial arthritic specimens can be diagnosed by crystal-type identification performed in cytopathology laboratories by the use of simple methods. These methods involve wet coverslipped preparations of fresh fluid specimens or sediments and compensated polarizing microscopy, which can be performed with a routine microscope equipped with polarizing filters and a substitute compensator. Details of the methodology are described. The morphologic characteristics of the crystals are described in cases of gout, pseudogout and arthritis of other types in which secondary calcifications are present.