Oxaliplatin-related thrombocytopenia mimicking myelodysplastic syndrome

Oxaliplatin-related thrombocytopenia

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A 67-year-old male patient with rectal cancer had received oxaliplatin, levofolinate calcium, and fluorouracil chemotherapy regimen plus bevacizumab for 9 months. Four weeks after the latest 16^th cycle of chemotherapy, the laboratory findings were as follows: white blood cell count, 5,440/μL; hemoglobin level, 12.1 g/dL; and platelet count (Plt), 3.8 × 10⁴/µL. A bone marrow aspiration smear revealed a nucleated cell count of 34,000/µL and a megakaryocyte count of 12.5 /µL. The bone marrow aspiration smear revealed the presence of a normal megakaryocyte, mononuclear megakaryocyte, micromegakaryocyte, and megakaryocyte with separated nuclei. Granulocytes and erythroblasts revealed no myelodysplasia. A cytogenic analysis revealed no chromosomal abnormalities. Chemotherapy was discontinued. Consequently, his platelet count increased to 9.6 × 10⁴/µL. Subsequently, a chemotherapy regimen, consisting of levofolinate calcium and fluorouracil plus bevacizumab, was restarted, which caused no severe thrombocytopenia. Myelodysplasia in megakaryocytes as well as bone marrow suppression may have caused thrombocytopenia. Finally, he was diagnosed with oxaliplatin-related thrombocytopenia, not myelodysplastic syndrome. Clinicians should be aware that some cases of oxaliplatin-related thrombocytopenia can be safely treated with oxaliplatin withdrawal.