Objective: To investigation the diagnostic utility of tyrosine hydroxylase (TH) immunohistochemically as a marker of peripheral neuroblastic tumors(pNT). Methods: The study included 1 024 cases, 643 primary and metastatic pNT cases, 381 non-pNT cases, including small round cell tumors such as primitive neuroectodermal tumor (PNET), rhabdomyosarcoma, lymphoma, nephroblastoma, as well as other more common tumors (medulloblastoma, hepatoblastoma, pleuropulmonary blastoma, renal clear cell sarcoma, Langerhans cell histiocytosis, lipoblatoma etc). Tissue slides of these 1 024 cases were stained with TH and other common antibodies to evaluate whether TH was useful to identify pNT. Results: TH showed cytoplasmic staining in 100.0% (643/643) of pNT and 3.9% (15/381) of non-pNT. TH expression was seen in some poorly differentiated and undifferentiated tumors with focal or scattered patterns. In some cases, more scattering was seen in neuroblastoma with poor differentiation. The sensitivity, specificity, positive predictive value and negative predictive value of TH was 100.0% (643/643), 96.1%(366/381), 97.7%(643/658) and 100.0% (366/366), respectively. There was no TH expression in the 248 cases of other small round cell tumors (PNET, rhabdomyosarcoma, lymphoma, etc), thus suggesting TH was useful to differentiate between PNET and neuroblastoma. As CD99 was positive in 95% PNET, some PNET would be CD99 negative. In those cases, particularly with diffuse rosettes forming, TH immunostaining would be useful. Conclusion: TH is sensitive and specific for pNT in the differential diagnosis from other tumors of childhood and shows high diagnostic utility.
目的： 探讨酪氨酸羟化酶(TH)在外周神经母细胞性肿瘤中的表达及其意义。 方法： 除诊断常用抗体外，入选1 024例病例均用免疫组织化学方法标记TH，其中原发及转移的外周神经母细胞性肿瘤共643例，其他非外周神经母细胞性肿瘤381例，包括常见的小细胞恶性肿瘤，如原始神经外胚层肿瘤(PNET)、横纹肌肉瘤、淋巴瘤、肾母细胞瘤等，及其他各器官/系统常见肿瘤：髓母细胞瘤、肝母细胞瘤、胸膜肺母细胞瘤、肾透明细胞肉瘤、朗格汉斯细胞组织细胞增生症、脂肪母细胞瘤等。 结果： (1)TH在643例原发及转移的外周神经母细胞性肿瘤中均呈瘤细胞胞质阳性表达，阳性表达率为100.0%(643/643)；非外周神经母细胞性肿瘤381例中，TH阳性例数为15例，阳性表达率为3.9%(15/381)。(2)部分分化差型的神经母细胞瘤和大多数未分化型的神经母细胞瘤中，TH呈部分或小灶状表达，即越是分化差的肿瘤细胞TH的阳性表达细胞数可能越少。(3)1 024例病例中，TH在外周神经母细胞性肿瘤中的表达敏感性为100.0%(643/643)，特异性为96.1%(366/381)，阳性预测值为97.7%(643/658)，阴性预测值为100.0%(366/366)。(4)TH在248例其他小细胞恶性肿瘤(包括PNET、横纹肌肉瘤、淋巴瘤等)中无阳性表达，尤其对于PNET与神经母细胞瘤的鉴别，CD99在95%的PNET中表达，对于CD99阴性的弥漫片状或有明显菊形团形成的小圆细胞肿瘤中如TH阳性表达与否对于两种肿瘤的鉴别有用。 结论： TH标记外周神经母细胞性肿瘤时，具有较高的特异性及敏感性，可以作为神经母细胞性肿瘤的辅助诊断及鉴别诊断一线抗体使用。.
Keywords: Diagnosis, differential; Immunohistochemistry; Neuroblastoma; Tyrosine hydroxylase.