A simple baker's cyst? Tocilizumab remits paraneoplastic signs and controls growth of IL-6-producing angiomatoid malignant fibrous histiocytoma

摘要

Sir, A 47-year-old male presented with severe systemic inflammatory response syndrome. A year previously he had noticed a painless swelling in the right fossa poplitea interpreted as Baker's cyst. Laboratory analysis documented CRP (97mg/l), ESR (102 mm/h), haemoglobin (98 g/l), slightly elevated liver enzymes and hyperferritinae-mia (1236mug/l), but no autoantibodies. Diagnostic workup comprised bone marrow aspiration, liver biopsy, MRI angiography of the thorax and abdomen, temporal artery biopsy, upper and lower gastrointestinal (Gl) endoscopy and biopsies to search for Whipple's disease, tuberculosis and malignancy. Differential diagnoses such as adult Still's disease or occult vasculitis were discussed.