Late recurrence of ewing sarcoma during pregnancy: a report of 2 cases

Ewing sarcoma is the second most common type of malignant bone tumor in children and young adults. We report 2 patients with a history of Ewing sarcoma who were diagnosed with recurrent tumor during or immediately after pregnancy. To determine whether the hormonal milieu of pregnancy might have contributed to recurrence, we performed immunohistochemistry for estrogen and progesterone receptors on available tumor tissue. These receptors were not detected by immunohistochemistry. Increased medical surveillance during pregnancy may have resulted in ascertainment of recurrence in these 2 patients.