MALIGNANT JOINT EFFUSIONS SECONDARY TO SOLID TUMOR-METASTASIS

We describe the case of a patient with breast cancer who developed bil ateral malignant knee effusions, and review the English language liter ature. Patients with solid tumors who develop malignant joint effusion s are rare; 27 cases have been reported (including our patient). The k nee is the predominant site of joint involvement (p < 0.001). Synovial fluid (SF) analysis often demonstrates noninflammatory bloody effusio n. Synovial biopsy was positive in 11 of 16 cases in which it was perf ormed. SF cytology was positive in one half of cases in which it was o btained. Arthritis secondary to metastasis is a poor prognostic findin g. A strong clinical suspicion is necessary to make the diagnosis; SF cytology or synovial biopsy can confirm it.