High‐Dose Continuous Infusion Ifosfamide as Effective Palliation in a Patient With Relapsed Ewing Sarcoma With Bone Marrow Infiltration and Severe Thrombocytopenia: A Case Report

Background Ewing sarcoma is a rare primary mesenchymal tumor of the bone that requires an intensive multimodal therapeutic approach. Multidrug chemotherapy regimens are also the backbone for relapsing/recurring Ewing sarcoma treatment, yet when the disease relapses as bone marrow infiltration, combination chemotherapy might be difficult to administer and prognosis is poor. Case This report describes the case of a 22‐year‐old patient with Ewing sarcoma who developed severe pancytopenia due to bone marrow infiltration, and who was treated with high‐dose continuous infusion ifosfamide, obtaining both clinical, radiological, and hematological response lasting for about 7 months. Conclusion To our knowledge, this is the first described case of a patient with bone marrow infiltration from Ewing sarcoma presenting with severe thrombocytopenia successfully managed with low‐dose continuous infusion ifosfamide, providing almost 7 months of progression‐free survival. Considering the very dismal prognosis of Ewing sarcoma relapsing with bone marrow infiltration, this case might be of help when decision‐making is required in this setting.