小儿肾脏原始神经外胚层肿瘤一例及文献复习

Pediatric primitive nem-oectodermal kidney tumor：case report and literature review

目的报道1例发生在儿童左。肾的原始神经外胚层肿瘤（PNET），并通过文献复习，提高临床医师对此罕见疾病的认识。方法通过回顾性分析1例发生在儿童肾脏的PNET的临床表现、病理形态特点及免疫表型特征，并结合相关文献复习。结果术前未能明确诊断，术后经病理证实为PNET。男性患儿，7岁，因左腹部疼痛入院，影像学发现肾占位，行肾切除术。光镜下，肿瘤由核圆浓染、形态一致的原始小圆细胞组成，瘤细胞弥漫成片分布，形成特征性的Homer-Wright菊形团结构，核分裂象易见，可见大片坏死。免疫组化示：突触素（Syn）、神经元特异性烯醇化酶（NES）和波纹蛋白（Vimentin）阳性，而CgA、CD99、S-100、Melan-A、HMB45、CK、EMA等均阴性。患儿术后予环磷酰胺、阿霉素及长春新碱化疗及放疗。3个月后失去随访。结论发生在儿童肾脏的PNET是一种临床上非常罕见的小圆细胞恶性肿瘤，高度恶性且极易复发和转移，术前常被误诊为肾母细胞瘤，主要依靠组织病理学和免疫组织化学确诊。目前主要治疗方法是手术切除加术后化疗，采用合理的综合治疗方案可延长生存期。

Objective To report a clinical case of pediatric primitive neuroectodermal kidney tumor （PNET）, review the relevant literatures and raise its clinician awareness. Methods The clinical data, histological features and immunohistochemical profiles were studied along with a review of literature reports. Results With an indefinite preoperative diagnosis, this case was confirmed by postoperative pathology. This 7-year-old boy was hospitalized for left abdominal pairL Renal mass on CT was treated by nephrectomy. Microscopically, the tumor was characterized predominantly by primitive uniform small round cells and dense sheet or nest-like structures surrounded by sparse fibrovascular strorna. Pseudorosettes or Homer-Wright rosettes were observed, as well as necrosis and mitoses. Immunohistochemical staining showed： Syn, NES and Vimentin were positive while CgA, CD99,S-100, Melan-A, HMtMS, CK and EMA all negative. He received a chemotherapy regimen of cyclophosphamide,adriamycin and vincristine plus radiotherapy. After 3 months, he became lost to follow-ups. Conclusions Primary pediatric renal PNET is highly malignant and susceptible to recurrence and metastasis. It is often misdiagnosed preoperatively as Wilms tumor and a definite diagnosis depends on histopathology and immunohistochemistry. The major treatment is surgical resection plus postoperative chemotherapy. However, an improved overall survival may be obtained if combined modality treatment is adequately applied.