Primary thoracic myxoid variant of extrarenal rhabdoid tumor in childhood
Primary thoracic myxoid variant of extrarenal rhabdoid tumor in childhood
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DOI：
10.1080/15513810600908388
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发表时间：
2006-05-01
影响因子：
1.1
通讯作者：
Sebire, N. J.
中科院分区：
文献类型：
--
作者：
Fowler, D. J.;Malone, M.;Sebire, N. J.
原发性肾外横纹肌样肿瘤（RT）现在被认为是一个特殊的实体在儿科肿瘤病理实践。我们提出一个不寻常的病例小细胞黏液样变的胸部RT在婴儿和突出的重要性，最近分子发展的诊断这些肿瘤。1例8个月大的婴儿有短暂的咳嗽史和呼吸短促。影像学显示右侧有一个大肿块占据了大部分胸腔。肿块经皮穿刺活检显示组织碎片由恶性肿瘤组成，主要为“小卵形细胞”表型和广泛的粘液样改变，肿瘤细胞呈小巢状和岛状；偶尔细胞显示开放的泡状核，突出的核仁和嗜酸性细胞质包涵体。免疫组化染色显示细胞角蛋白局灶性强细胞质阳性，局灶性强副核细胞质波形蛋白阳性，INI1染色在对照组织中显示正常核阳性，而在肿瘤细胞核中显示阴性。电镜显示特征性的中间丝的核旁螺旋，证实了肾外恶性肿瘤的诊断。恶性横纹肌样瘤的诊断可能是困难的，特别是在病例中，如本病例，主要是小细胞黏液样表型。细胞角蛋白和静脉蛋白的特征性表达模式为诊断提供了强有力的线索，现在使用INI1抗体甚至可以在针芯活检中进行明确诊断。
Primary extrarenal rhabdoid tumors (RT) are now recognized as a specific entity in pediatric oncological pathology practice. We present an unusual case of a small cell myxoid variant of a thoracic RT in an infant and highlight the importance of recent molecular developments in the diagnosis of these tumors. An 8-month-old child presented with a short history of cough and shortness of breath. Imaging demonstrated a large mass occupying the majority of the thoracic cavity on the right side. A percutaneous needle biopsy of the mass showed fragments of tissue composed of malignant tumor with a predominant "small ovoid cell" phenotype and extensive myxoid change, with small nests and islands of tumor cells; occasional cells demonstrated open vesicular nuclei, prominent nucleoli, and eosinophilic cytoplasmic inclusions. Immunohistochemical staining revealed focal strong cytoplasmic positivity for cytokeratin, focal strong paranuclear cytoplasmic vimentin positivity, and INI1 staining showed normal nuclear positivity in control tissues but was negative in tumor cell nuclei. Electron microscopy demonstrated characteristic paranuclear whorls of intermediate filaments confirming the diagnosis of extrarenal malignant RT. The diagnosis of malignant rhabdoid tumor may be difficult, particularly in cases, such as the present, with a predominant small-cell myxoid phenotype. The characteristic expression patterns of cytokeratin and vimentin provide strong clues to the diagnosis, and the use of INI1 antibody now makes definitive diagnosis possible even on needle core biopsies.