儿童和青少年淋巴瘤反应性胸腺增生的预测因素及其预后价值-Eur J Radiol. 2018 ... .. ...

背景：反应性胸腺增生（RTH）见于儿童和青少年接受化疗的各种恶性肿瘤。然而，目前尚不清楚为什么这种情况只发生在一些患者身上。本研究的目的是在接受淋巴瘤化疗的儿童和青少年中确定RTH的预测因素，并确定RTH对预后的影响。

方法：回顾性分析126例淋巴瘤患者的病历（2007年10月-2012年10月）。根据不同的诊断标准将患者分为两组，即初诊年龄（2-12岁vs.13-18岁）；基线检查时是否有胸腺浸润（是vs.否）；接受纵隔放疗（是vs.否）。采用Kaplan-Meier方法和多变量Cox回归模型分析RTH的预测因素。根据随访中RTH的发生情况将患者分为两组，采用Kaplan-Meier生存分析法分析RTH的预后价值。

结果：2～12岁组从治疗结束到RTH的时间较13～18岁组短（中位数：3个月vs.16个月），RTH发生率较高（97.1%vs.60.3%，P<0.001）。淋巴瘤胸腺非浸润组从治疗结束到RTH的时间较淋巴瘤浸润组短（中位数：4个月vs.22个月），RTH发生率较高（88.2%vs.57.6%，P<0.001）。非纵隔放疗组RTH发生率明显高于纵隔放疗组（84.7%vs12.5%，P<0.001）。多因素Cox回归分析显示，低年龄、基线时无淋巴瘤胸腺浸润、无纵隔放疗是RTH的预测因素（P<0.05）。RTH组的复发率低于非RTH组（13.9%对40%），且从治疗结束到复发的时间更长（中位数：10个月对5个月，P<0.001）。

结论：年龄小、基线检查时无淋巴瘤胸腺浸润、无纵隔放疗是儿童和青少年RTH的预测因素。RTH可能是一个积极的预后因素。

关键词：青少年；儿童；淋巴瘤；预后；胸腺增生。

图1.淋巴瘤引起的胸腺浸润。男，10岁。前纵隔肿块边界不清，周围脂肪间隙模糊，密度均匀，PET/CT扫描FDG摄取均匀，病理诊断为T淋巴细胞淋巴瘤。Fig. 1. Thymic infiltration by lymphoma. Male, aged 10 years. Anterior mediastinal mass with poorly-circumscribed, blurred peripheral fat gap, homogeneous density, homogeneous FDG uptake in PET/CT scanning and pathological diagnosis of T-lymphoblastic lymphoma.

图2。反应性胸腺增生（RTH）。女性，7岁，诊断为非霍奇金淋巴瘤。治疗后完全缓解。肿瘤治疗3个月后，PET/CT扫描显示一个新的前纵隔肿块边界清楚，周围脂肪间隙清晰，密度均匀，FDG摄取均匀。Fig. 2. Reactive thymic hyperplasia (RTH). Female, aged 7 years, diagnosed with non-Hodgkin’s lymphoma. Achieved complete remission following therapy. A new anterior mediastinal mass appeared that was well-circumscribed, with a clear peripheral fat gap, homogeneous density, and homogeneous FDG uptake in PET/CT scanning after 3 months of antitumor therapy.

Background: Reactive thymic hyperplasia (RTH) is seen in children and adolescents receiving chemotherapy for various malignancies. However, it is not clear why this occurs only in some patients. The aim of this study was to identify the predictors for RTH in children and adolescents receiving chemotherapy for lymphoma and to determine the effect of RTH on prognosis.

Methods: We reviewed the medical records of 126 lymphoma patients (October 2007-October 2012). The patients were divided into two groups according to different criteria, i.e., age at initial diagnosis (2-12 years vs. 13-18 years); presence of thymic infiltration at baseline (yes vs. no); and receipt of mediastinal radiotherapy (yes vs. no). The Kaplan-Meier method and multivariate Cox regression model analysis were used to analyze predictors for RTH. Further, patients were divided into two groups according to the occurrence of RTH during follow-up, and Kaplan-Meier survival analysis was used to analyze the prognostic value of RTH.

Results: The 2-12-year-old group had a shorter duration from the end of therapy to RTH than the 13-18-year-old group (median: 3 months vs. 16 months) and a higher rate of RTH (97.1% vs. 60.3%, P < 0.001). The lymphoma thymic non-infiltration group had a shorter duration from the end of therapy to RTH than the lymphoma infiltration group (median: 4 months vs. 22 months), and a higher rate of RTH (88.2% vs. 57.6%, P < 0.001). The non-mediastinal radiotherapy group had higher rate of RTH than the mediastinal radiotherapy group (84.7% vs. 12.5%, P < 0.001). Low age, absence of thymic infiltration by lymphoma at baseline, and absence of mediastinal radiation were predictors for RTH by multivariate Cox regression analysis (P < 0.05). The RTH group had a lower recurrence rate than the non-RTH group (13.9% vs. 40%), and a longer duration from the end of therapy to recurrence (median: 10 months vs. 5 months, P < 0.001).

Conclusions: Younger age, absence of thymic infiltration by lymphoma at baseline and absence of mediastinal radiotherapy are predictors for RTH in children and adolescents. RTH may be a positive prognostic factor.

Keywords: Adolescents; Children; Lymphoma; Prognosis; Thymic hyperplasia.