[Joint effusion findings in alkaptonuric arthropathy (ochronosis)].

Findings are presented within the synovial effusion of a 55-year-old man with numerous, macroscopically visible, brownish-blackish rods of a length from 3 to 5 mm. The combined cytologic as well as histologic results of synovial fluid investigations, including the investigation of a synovial fibrin clot, led to the diagnosis of ochronosis. Similar findings were described previously two times only. The morphologic diagnosis ochronosis was proved to be well founded by the subsequent investigation of the patient's urine. Hints are also given for diagnosis of ochronotic synovial effusions.