Loss of INI1 Expression is Characteristic of Both Conventional and Proximal-type Epithelioid Sarcoma
Loss of INI1 Expression is Characteristic of Both Conventional and Proximal-type Epithelioid Sarcoma
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DOI：
10.1097/pas.0b013e3181882c54
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发表时间：
2009-04-01
影响因子：
5.6
通讯作者：
Fletcher, Christopher D. M.
中科院分区：
文献类型：
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作者：
Hornick, Jason L.;Dal Cin, Paola;Fletcher, Christopher D. M.
INI 1（hSNF 5/SMARCB 1）是位于染色体22q11.2上的SWI/SNF染色质重塑复合物的成员，在严格定义的婴儿恶性横纹肌样瘤（MRT）中缺失或/或突变。最近的研究表明，一些上皮样肉瘤（ES）也显示INI 1失活。然而，很少的情况下，ES进行了研究，并在其他上皮样恶性肿瘤中的INI 1表达尚未进行系统的研究。本研究的目的是评估免疫组化表达的INI 1 ES相比，组织学模拟。我们评估了350个肿瘤：136个ES，包括64个传统的（“远端”）ES，64例近端型ES，8例具有常规和近端型ES的杂交特征; 54例转移性癌转移性睾丸胚胎癌12例（肺22例，乳腺6例，胃6例，结直肠5例，肾5例，前列腺5例，胰腺5例）; 20例转移性黑色素瘤20例上皮样间皮瘤：20例上皮样血管瘤; 10例上皮样血管内皮瘤; 24例上皮样恶性外周神经鞘瘤（MPNST）; 22例软组织肌上皮癌; 7例间变性大细胞淋巴瘤; 5例组织细胞肉瘤;对照组10例（脑4例，肝3例，软组织2例，肾1例）。在高压锅热诱导的表位修复后，使用单克隆抗体BAF 47（BD Biosciences）进行免疫组织化学。总的来说，136例ES病例中有127例（93%）显示INI 1表达完全缺失，包括58例（91%）常规ES，61例（95%）近端型ES和所有8例（100%）混合型ES。在非ES病例中，12例（50%）上皮样MPNST也显示INI 1丢失，2例（9%）肌上皮癌和所有对照MRT病例也显示INI 1丢失。INI 1表达在所有其他肿瘤类型中均完整。总之，与婴儿期MRT相似，INI 1表达缺失是常规型和近端型ES的特征，在> 90%的病例中检测到。此外，50%的上皮样MPNST和偶尔的肌上皮癌也对INI 1呈阴性。INI 1的免疫染色可用于在适当的情况下确认ES的诊断。INI 1表达的缺失也可能有助于区分上皮样MPNST和转移性黑色素瘤。
INI1 (hSNF5/SMARCB1), a member of the SWI/SNF chromatin remodeling complex located on chromosome 22q11.2, is deleted or/or mutated in strictly defined malignant rhabdoid tumors (MRT) of infancy. Recent Studies Suggest that some epithelioid sarcomas (ES) also show inactivation of INI1. However, very few cases of ES have been studied, and INI1 expression in other epithelioid malignant neoplasms has not been examined systematically. The purpose of this study was to evaluate the immunohistochemical expression of INI1 in ES compared with histologic mimics. We evaluated 350 tumors: 136 ES, including 64 conventional ("distal") ES, 64 proximal-type ES, and 8 with hybrid features of conventional and proximal-type ES; 54 metastatic carcinomas (22 from lung, 6 breast, 6 stomach, 5 colorectum, 5 kidney, 5 prostate, 5 pancreas) 12 metastatic testicular embryonal carcinomas; 20 metastatic melanomas 20 epithelioid mesotheliomas: 20 epithelioid angiosarcomas; 10 epithelioid hemangioendotheliomas 24 epithelioid malignant peripheral nerve sheath tumors (MPNST); 22 myoepithelial carcinomas of soft tissue; 7 anaplastic large cell lymphomas; 5 histiocytic sarcomas; and 10 control MRT of infancy (4 brain, 3 liver, 2 soft tissue, I kidney). Immunohistochemistry was performed following pressure cooker heat-induced epitope retrieval using monoclonal antibody BAF47 (BD Biosciences). In total, 127 of 136 (93%) ES cases showed complete absence of INI1 expression, including 58 (91%) conventional ES, 61 (95%) proximal-type ES, and all 8 (100%) hybrid ES. Of the non-ES cases, 12 (50%) epithelioid MPNST also showed loss of INI1, as did 2 (9%) myoepithelial carcinomas and all control MRT cases. INI1 expression was intact in all other tumor types examined. In conclusion, similar to MRT of infancy, loss of INI1 expression is characteristic of both conventional and proximal-type ES, being detected in > 90% of cases. Moreover, 50% epithelioid MPNST and occasional myoepithelial carcinomas are also negative for INI1. Immunostaining for INI1 can be used to confirm the diagnosis of ES in the appropriate context. Loss of INI1 expression may also be helpful to distinguish epithelioid MPNST from metastatic melanoma in a subset of cases.