The importance of urgent cytological examination of synovial fluids in differentiation inflammatory and non-inflammatory joint diseases.

The aim of this study was to imply the possibilities of the urgent cytological examination of synovial fluids in differential diagnosis of arthropathies and to motivate the clinicians to use this method. It gave valuable information particularly with respect to differentiate the inflammatory and non-inflammatory joint diseases. This study included 115 synovial fluids obtained by fine needle aspiration (FNA) of the swollen knee from the patients in the period between 2003 and 2008. At our department the urgent cytological examination of the synovial fluids consisted of macroscopic analysis that includes volume, colour, clarity, viscosity and mucin clot test, native microscopic analysis for crystals and tissue fragments, counting the total nucleated cell count and semiquantitative microscopic analysis for neutrophil granulocyte percentage on the slides stained with Hemacolor rapid staining. All cytological analyses were done within one hour since FNA. According to our results the clarity, viscosity, mucin clot test, the total nucleated cell count and the neutrophil granulocyte percentage enabled distinction between inflammatory and non-inflammatory diseases with statistically significant difference at the 0.01 level but we could not differentiate these two groups of illnesses according to volume and colour. In inflammation the total nucleated cell count and the neutrophil granulocyte percentage was greater than in non-inflammation, the clarity was only translucent and opaque, the viscosity was low and the mucin clot test was negative. In non-inflammatory diseases the clarity varied from transparent to opaque, the total nucleated cell count and the neutrophil granulocyte percentage was smaller than in inflammatory diseases, the viscosity was high and consequently the mucin test was highly positive in all samples. Crystals were detected in only 12 samples of synovial fluids, mostly in inflammation and they were all monosodium urate (MUS) so we could diagnose gout. We could conclude that the urgent cytological analysis of the synovial fluid is a very useful, simple and reliable basic diagnostic screening test in differentiation inflammatory and non-inflammatory joint diseases and we recommended using it as the initial test in the diagnostic procedure of these illnesses using our protocol.