Migratory lung lesions in an elderly man

In the absence of evidence of infection with the hepatitis C virus (HCV), detecting the immunological disorder of mixed cryoglobulinaemia is a challenge. Only after extensive investigation did we suspect that our patient's recurrent acute dyspnoea, lower limb paraesthesia and renal impairment with active urinary sediment were attributable to the rare phenomenon of non-HCV-related mixed essential cryoglobulinaemia - our suspicion was confirmed by significant serum levels of cryoglobulins.