摘要目的:探讨纵隔T淋巴母细胞淋巴瘤/白血病（T-LBL/ALL）的临床病理学特征及预后。方法:收集郑州大学第一附属医院病理科2011年8月1日到2018年12月31日61例纵隔T-LBL/ALL的病例，回顾性分析其临床、影像、病理特点及预后。结果:男性46例，女性15例，男女比约3∶1；年龄5~71岁，中位年龄24岁，平均年龄24.5岁；影像学表现为纵隔软组织肿块（58例）或纵隔多发肿大融合淋巴结（1例），体积较大，直径4.9~18.3 cm，2例未获得影像资料。患者主要表现为上腔静脉综合征（咳嗽、呼吸困难、颜面部或颈部水肿）、胸闷或胸痛症状，约1/3患者出现B症状。61例标本均为穿刺活检，其中2例并有手术切除标本。组织形态学见胸腺组织上皮网结构破坏或完全消失，大量肿瘤性淋巴细胞弥漫浸润,并可见脂肪组织浸润、星空现象、列兵样排列、间质胶原增生硬化及肿瘤细胞挤压等，少部分病例出现小灶肿瘤性坏死。肿瘤性淋巴细胞小至中等大小，圆形，细胞质少，核稍扭曲，圆或卵圆形，染色质细，核仁不明显或有小核仁。免疫组织化学标志物：肿瘤细胞表达CD7（100%，33/33）、末端脱氧核苷酸转移酶（TDT，93.4%，57/61）、CD99（83.3%，25/30）、CD1a（4/7）、CD10（8/18）、CD34（13.2%，5/38），不表达B细胞标志物CD20、PAX5及粒单核细胞标志物髓过氧化物酶（MPO），Ki-67阳性指数通常大于50%。1例做了T细胞受体重排，结果阳性。临床治疗采用化疗方案，Hyper-CVAD（环磷酰胺、长春地辛、地塞米松和表柔比星）方案最多（60.4%，32/53），其次为BFM-90（50.9%，27/53），部分选取以上2种及其他治疗方案。61例患者中6例失访，55例获得随访结果，存活26例（47.3%），5年生存率为50.6%。统计学显示患者预后与国际预后指数、患者的发病年龄、性别、肿块大小均无明确相关性。结论:纵隔T-LBL/ALL少见，临床送检以穿刺活检标本为主，组织学形态诊断困难，需紧密结合临床特点及免疫组织化学综合诊断。免疫组织化学广谱细胞角蛋白（CKpan）、TDT、CD99、CD7、CD3、PAX5、CD34、CD10、Ki-67九种抗体的联合应用有助于大多数病例的诊断。

abstractsObjective:To investigate the clinicopathologic features and prognosis of mediastinal T lymphoblastic lymphoma/leukemia (T-LBL/ALL).Methods:Sixty-one patients with mediastinal T-LBL/ALL diagnosed at First Affiliated Hospital of Zhengzhou University from August 1, 2011 to December 31, 2018 were enrolled. Their clinical, pathological, imaging features and prognosis were retrospectively analyzed.Results:Of the 61 patients with mediastinal T-LBL/ALL, 46 were male and 15 were female, with a male to female ratio of approximately 3∶1, aged 5 to 71 years (median 24 years, average of 24.5 years). Radiological findings were mediastinal soft tissue masses (58 cases) or mediastinal multiple enlarged lymph nodes (1 case). The tumor had a diameter of 4.9 to 18.3?cm in size, and data of 2 cases was unavailable. The patient′s main symptoms were superior vena cava syndrome (cough, dyspnea, facial or neck edema), shortness of breath and chest pain, while about 1/3 of patients developed B symptoms (high fever, night sweats or significant weight loss). All 61 cases were biopsy specimens, and 2 of the tumors were later resected. Histopathologic examination showed that the thymic tissue epithelial network structure was destroyed or completely disappeared. A large number of lymphocytoid tumor cells were diffusely infiltrative, with infiltration into adipose tissue, starry sky phenomenon, linear-like arrangement, interstitial collagen hyperplasia and tumor cell extrusion. Focal tumor necrosis was present in some cases. Tumor cells were overall small to medium in size. They had little cytoplasm, slightly distorted, round or oval-shaped nuclei, fine chromatin, and innocuous/small nucleoli. Immunohistochemical studies showed that the tumor cells expressed CD7 (100%, 33/33), TDT (93.4%, 57/61), CD99 (83.3%, 25/30), CD1a (4/7), CD10 (8/18), CD34 (13.2%, 5/38), but did not express B cell markers (CD20 and PAX5) or granulocyte monocyte marker (MPO). The Ki-67 proliferation index was usually greater than 50%. One case was tested for TCR clonal rearrangement, which was positive. Several hemotherapy regiments were used. Hyper-CVAD (cyclophosphamide, vindesine, dexamethasone, and epirubicin) were most frequently administrated (60.4%, 32/53), followed by BFM-90 (50.9%, 27/53). Some patients were treated with the above two and other treatment options. Follow-up data were available in 55 of the 61 patients, and 26 patients (47.3%) survived. The average five-year survival rate was 50.6%. The patient′s prognosis was not significantly related to the International Prognostic Index, age of onset, gender, or tumor size.Conclusions:The mediastinal T-LBL/ALL is rare, and most of its specimens are needle biopsies. The histological morphology is often difficult to interpret, while the addition of clinical features and immunohistochemistry may help. The combination of CKpan, TDT, CD99, CD7, CD3, PAX5, CD34, CD10, and Ki-67 immunohistochemicl studies may assist in diagnosis of the most cases.