Leukemic reticuloendotheliosis. A failure of monocyte production.

In five cases of leukemic reticuloendotheliosis studied, profound monocytopenia was demonstrable. In 48 normal subjects, monocyte counts ranged from 215 to 921 per cubic millimeter, whereas in the five patients with leukemic reticuloendotheliosis, the counts ranged from 0 to 17 per cubic millimeter. The properties of the "hairy" cell are consistent with those of an incompletely developed monocyte. The susceptibility to infection, characteristics of these patients, may result from a lack of normal monocytes in blood and tissues.