[Value of cytological analysis of the synovial fluid in multicentric reticulohistiocytosis. A case].

The authors report the case of a patient who had both multicentric reticulohistiocytosis--a systemic disease characterized by symmetric polyarthritis and papulonodular skin lesions--and an ovarian adenocarcinoma. Synovial fluid analysis found histiocytes with a ground-glass cytoplasm, binucleate giant cells, and undifferentiated cells undergoing mitosis. PAS-positive, diastase-resistant cells similar to the synovial fluid histiocytes were seen in the synovial and cutaneous biopsy specimens. These findings established the diagnosis of multicentric reticulohistiocytosis and suggested an underlying malignancy. Whether or not multicentric reticulohistiocytosis is a paraneoplastic syndrome remains unsettled. However, our report provides evidence that synovial fluid analysis can be helpful not only for the early diagnosis of multicentric reticulohistiocytosis but also for suggesting the presence of an underlying tumor, especially when arthritis is the presenting symptom.