Cryocrystalglobulinemia in hairy cell leukemia.

A patient with hairy cell leukemia (leukemic reticuloendotheliosis) was noted to have a spurious leukocytosis caused by a spontaneously crystallizing cryoglobulin. The cryoprotein was identified as IgG lambda. An intracytoplasmic immunoglobulin demonstrable within the hairy cell was also IgG lambda. The cryoglobulin spontaneously disappeared over a four day period. A reliable automated count on the Coulter Model S could be obtained by prewarming the blood specimen to 37 C.