A 66-year-old patient developed leukocytosis, neutrophilia and monocytosis following surgery for gastric carcinoma. The polymorphonuclear cells showed a marked shift to the right and abnormally hypersegmented or pyknotic nuclei, whereas the monocytes were vacuolized. The bone marrow was hypcrccllular with an increased number of multilobed polymorphonuclear cells. This myeloid cell defect is compatible with the nuclear abnormalities described as myelokathexis. The combination of the nuclear abnormalities of the polymorphonuclear cells with persistent monocytosis suggests the possibility of a paraneoplastic variant of myelodysplasia.