Kim Jee Young, Im Soo Ah, Lee Ju Hyun, Lee Jae Wook, Chung Nak Gyun, Cho Bin
Department of Radiology, Seoul St. Mary's hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Department of Pediatrics, Seoul St. Mary's hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Iran J Pediatr. 2016 May 28;26(3):e1711. doi: 10.5812/ijp.1711. eCollection 2016 Jun.
Extramedullary relapse (EMR) is a recurrence of leukemia in sites other than the bone marrow, and it exhibits a relatively rare presentation of relapse of acute leukemia. However, EMR is an important cause of treatment failure among patients with acute leukemia. Therefore, early detection of these relapses may improve the prognosis.
To describe the disease-related demographic and clinical features and radiologic findings for children diagnosed with EMR in acute leukemia.
The study was based on 22 children (M: F = 14: 8; mean age 7.30 (2.1 - 15.7) years) with 8 acute myeloid leukemia (AML) and 14 acute lymphoid leukemia (ALL) who had experienced an EMR. Age, gender, clinical symptoms, initial extramedullary disease (EMD), French-American-British (FAB) morphology, cytogenetics, time to and site of EMR, concurrent bone marrow relapse (BMR), radiologic findings, and outcomes were evaluated.
No definite relationship was found between initial EMD and EMR. A predilection for AML to relapse in the central nervous system (CNS), except for the CSF and bone, and for ALL to relapse in the CSF and kidney seemed to occur. Patients with EMR had a significantly higher incidence of t(8: 21) cytogenetics and FAB M2 and L1 morphologies. EMR accompanied with concurrent BMR occurred in 31.8% of the patients, who exhibited a relatively grave clinical course. Radiologic findings were nonspecific and had a great variety of structure involved, including bulging enhancing mass in the CT scan, hypoechoic mass in the US, and enhanced mass-like lesion in the MRI.
Knowledge of the potential sites of EMR, their risk factors, and their clinical and radiologic features may be helpful in the early diagnosis of relapse and planning for therapy.
髓外复发（EMR）是白血病在骨髓以外部位的复发，是急性白血病相对少见的复发形式。然而，EMR是急性白血病患者治疗失败的重要原因。因此，早期发现这些复发可能改善预后。
描述急性白血病中诊断为EMR的儿童的疾病相关人口统计学和临床特征及影像学表现。
本研究基于22例经历EMR的儿童（男∶女 = 14∶8；平均年龄7.30（2.1 - 15.7）岁），其中8例为急性髓系白血病（AML），14例为急性淋巴细胞白血病（ALL）。评估了年龄、性别、临床症状、初始髓外疾病（EMD）、法美英（FAB）分型、细胞遗传学、EMR发生时间和部位、并发骨髓复发（BMR）、影像学表现及预后。
未发现初始EMD与EMR之间存在明确关系。AML似乎更倾向于在中枢神经系统（CNS）（脑脊液和骨骼除外）复发，而ALL更倾向于在脑脊液和肾脏复发。EMR患者t（8；21）细胞遗传学及FAB M2和L1分型的发生率显著更高。31.8%的患者发生了伴有并发BMR的EMR，其临床病程相对严重。影像学表现无特异性，涉及多种结构，包括CT扫描中突出的强化肿块、超声检查中的低回声肿块以及MRI检查中的强化肿块样病变。
了解EMR的潜在部位、危险因素及其临床和影像学特征可能有助于早期诊断复发并制定治疗方案。
