We describe the case of a patient with a particular form of presumably immu
ne-mediated encephalomyelitis associated with a monoclonal cold agglutin ga
mmapathy Systematic autopsy showed predominantly demyelinating lesions of t
he brain and spinal cord. The lesions were assumed to be the immune-mediate
d consequences of the underlying hematologic condition. Similarity with cer
tain paraneoplastic syndromes is underlined.