Artefacts associated with a cryoglobulin.

Abstract
A 70 year old man is described in whom the presence of a cryoglobulin caused a number of unusual laboratory features which were not recognized as being due to a cryoglobulin initially. Pseudoleucocytosis has been recognized in the past. However, the intracytoplasmic inclusion bodies have only rarely been described. The curious appearance of the ESR has not previously been described.