Metastatic lesions in the joint associated with acute inflammatory arthritis after dendritic cell immunotherapy for metastatic melanoma

A 47 year old man undergoing immunotherapy for metastatic melanoma with aut ologous dendritic cells pulsed with autologous tumour peptide and hepatitis a surface antigen developed acute left ankle arthritis. Gout and acute inf ection were excluded, and an autoimmune aetiology or occult metastasis were considered. The arthritis initially subsided with indomethacin, but the sy mptoms recurred 2 months later, and magnetic resonance imaging demonstrated metastatic melanoma of the left talus. Immunohistochemical staining of a c erebral metastatic deposit biopsied 1 week after the onset of arthritis dem onstrated T-cell and macrophage infiltration of the tumour. In addition, th e patient developed melanoma-specific delayed type hypersensitivity and cyt otoxic T-cell responses after vaccination. Thus, the monoarthritis represen ted an 'appropriate' inflammatory response directed against metastatic mela noma. (C) 2001 Lippincott Williams & Wilkins.