Chronic relapsing polyradiculoneuropathy in IgG lambda monoclonal gammopathy of undetermined significance (MGUS)--complete remission following carmustine treatment.

A previously healthy 43 year-old female developed IgG lambda monoclonal gammopathy of undetermined significance (MGUS) and ascending sensorimotor polyradiculoneuropathy which relapsed 11 times within 2 years. Marked improvement was noted repeatedly after plasmapheresis. However, on each occasion symptoms and signs of polyradiculoneuropathy recurred almost exactly 3 weeks after plasma-pheresis. Following 6 weeks of treatment with carmustine (70 mg/week), nearly complete recovery was established, which has persisted up to now (82 months after the end of therapy). The close temporal correlation between clinical relapse and recurrence of the IgG paraprotein and its permanent absence in stable clinical remission after carmustine treatment suggest a causal relationship between the paraprotein and the polyradiculoneuropathy. However, further studies are required to confirm this observation, as well as the efficacy of carmustine therapy.