Sasajima Toshio, Oda Masaya, Kinouchi Hiroyuki, Hatazawa Jun, Mizoi Kazuo
Department of Neurosurgery, Akita University School of Medicine, 1-1-1 Hondo, Akita-city, Akita 010-8543, Japan.
No Shinkei Geka. 2002 Jun;30(6):639-45.
A case of frontal atypical teratoid/rhabdoid tumor (AT/RT) was presented in the findings of single-photon emission computerized tomography (SPECT) using 201Tl-chloride (Tl) and 123I-metaiodobenzylguanidine (MIBG), and positron emission tomography using 18F-fluorodeoxyglucose (FDG) and (11C-methyl)-L-methionine (Met). A 16-year-old female had an episode of Jacksonian seizures one month prior to admission. CT scans showed an isodensity mass with heterogeneous enhancement in the left frontal lobe. MR images revealed a tumor with solid and cystic components and perifocal edema. SPECT demonstrated intense accumulation of Tl and MIBG in the enhancing lesion 15 min and 30 min after intravenous injection of tracers, respectively. The 6-hr delayed SPECT showed no retention of MIBG in the enhancing lesion. FDG-PET and Met-PET revealed high uptake of tracers in the enhancing lesion. Met did not accumulate in the frontal white matter, which appeared hyperintense on T2-weighted MR images. The patient underwent an uneventful extirpation of the solid mass, where Met had accumulated. Microscopically, the solid tumor contained rhabdoid cells, spindle-shaped cells resembling mesenchymal cells, and nests of small cells. The tumor cells were immunoreactive for vimentin, cytokeratin, and epithelial membrane antigen. The MIB-1 labeling index was 25%. The histological diagnosis was AT/RT. Postoperative course was uneventful. A dose of 32.4 Gy was administrated to the whole brain and a boost of 27.8 Gy to the T2-hyperintensity lesion. Five months after the radiotherapy, MRI showed neither abnormal enhancing lesions nor the T2-hyperintensity lesion. Multifarious studies using SPECT and PET are useful for differential diagnosis and for choosing optimal therapeutic strategy for this type of tumor.
本文报告了1例采用201Tl氯化物（Tl）和123I-间碘苄胍（MIBG）的单光子发射计算机断层扫描（SPECT）以及18F-氟脱氧葡萄糖（FDG）和（11C-甲基）-L-蛋氨酸（Met）的正电子发射断层扫描检查的额叶非典型畸胎样/横纹肌样瘤（AT/RT）病例。一名16岁女性在入院前1个月出现杰克逊癫痫发作。CT扫描显示左额叶有一等密度肿块，强化不均匀。磁共振成像（MR）显示肿瘤有实性和囊性成分以及灶周水肿。SPECT显示，静脉注射示踪剂后15分钟和30分钟，Tl和MIBG分别在强化病灶中强烈聚集。6小时延迟SPECT显示强化病灶中无MIBG滞留。FDG-PET和Met-PET显示强化病灶中示踪剂摄取高。Met未在T2加权MR图像上呈高信号的额叶白质中聚集。患者顺利切除了Met聚集的实性肿块。显微镜下，实性肿瘤包含横纹肌样细胞、类似间充质细胞的梭形细胞以及小细胞巢。肿瘤细胞波形蛋白、细胞角蛋白和上皮膜抗原免疫反应阳性。MIB-1标记指数为25%。组织学诊断为AT/RT。术后过程顺利。全脑给予32.4 Gy剂量放疗，对T2高信号病灶给予27.8 Gy的追加剂量。放疗后5个月，MRI显示既无异常强化病灶也无T2高信号病灶。使用SPECT和PET的多种研究有助于这种类型肿瘤的鉴别诊断和选择最佳治疗策略。
