[Cyclic thrombocytopenia associated with erythroid hypoplasia--a case].

We report the case of a 75-year-old woman with cyclic thrombocytopenia associated with erythroid hypoplasia. One platelet cycle lasted for about 28-30 days, with the platelet count fluctuating from 1.0 x 10(4)/microliter to 56.0 x 10(4)/microliter. Megakaryocyte count increased in the phase during which platelet count increased, and decreased in the phase during which platelet count decreased. Bone marrow colony formation was observed in serum-free agar, and megakaryocyte colony count was correlated with the platelet cycle. Platelet-associated immunoglobulin was in the normal range when platelet count increased, but increased when platelet count decreased. These findings suggest that the observed platelet count fluctuation was related to the production and destruction of platelet. Our patient also had erythroid hypoplasia, but her erythrocyte count did not fluctuate. This is the first reported case of cyclic thrombocytopenia and erythroid hypoplasia.