Diagnostic value of synovial fluid analysis in pigmented villonodular synovitis (PVS)- a proposal of diagnostic criteria

PVS is an idiopathic lesion that affects the synovial joints,tendons,sheats and bursea through the production of tumour-like growths. Diagnosis of PVS is difficult. Arthroscopy and biopsy together with microscopic examination are usually a base. According to our experience, cytologic features of synovial fluid are a very useful diagnostic tool in PVS.

Material and methods

Synovial fluids (SF) from the joints of 14 patients with biopsy-proven PVS were examined. Moreover in all the patients features of the disease were confirmed in surgical specimes. Synovial fluids were divided into three samples, for physicochemical analysis, bacteriological and cytologic findings, and placed in sterile tubes. For cytological examination MGG staining was used.

Results

SF analysis had revealed an inflammatory character of effusion. In all the cases synovial fluids were bloody and fragments of synovial villi in their sediments were observed as well as multinucleated giant cells, pseudomalignant cell, macrophages with phagocytized hemosiderin, foam cell and a few synoviocytes. Moreover the fat crystals were seen, under polarized light.

Conclusion

Cytological features of synovial fluid in PVS are in parallel with results of microscopic examination of joints tissues. In our opinion SF analysis should be the first step in the diagnopstic procedure in PVS. We propose the following criteria:

Major

• 1. the presence of bloody fluid with fragments of synovial villi in sediment

• 2. macrophages containing hemosiderin

• 3. pseudomalignant cells

Minor

• 1. multinucleated giant cells

• 2. foam cells

• 3. fat crystals

The diagnosis of PVS can be establish if all the major and at least one of the minor criteria are fulfilled.