Thomas de Montpréville Vincent, Quilhot Pauline, Chalabreysse Lara, De Muret Anne, Hofman Véronique, Lantuéjoul Sylvie, Parrens Marie, Payan Marie-José, Rouquette Isabelle, Secq Véronique, Girard Nicolas, Besse Benjamin, Marx Alexander, Molina Thierry Jo
Centre Chirurgical Marie Lannelongue, Département de Pathologie, Le Plessis Robinson, France.
Centre Chirurgical Marie Lannelongue, Département de Pathologie, Le Plessis Robinson, France.
Pathol Res Pract. 2015 Dec;211(12):996-1002. doi: 10.1016/j.prp.2015.10.005. Epub 2015 Oct 19.
Glucose-transporter-1 (Glut-1) may be a useful marker for differentiating B3 thymomas and thymic carcinomas. Since the literature is limited, we undertook a study to evaluate its diagnostic value in a series of thymic epithelial tumors.
Glut-1 expression was studied by the group of pathologists linked to the French national oncological network RYTHMIC. Immunostaining was performed on a whole section of one paraffin block in a series of 92 successive surgical specimens. Patterns (focal, zonal, diffuse) and intensity of Glut-1 expression were assessed and compared with WHO histological subtypes.
Expression was mainly restricted to epithelial cells. Immature T-lymphocytes were negative. A diffuse, moderate or strong staining was observed in most thymic carcinomas (15/16). In B3 thymomas (10/11) and in B3 thymomas borderline to thymic carcinomas (5/6), a moderate to strong zonal staining was observed at distance from vessels and fibrous septa. This pattern sometimes created the aspect of an anastomosing network in large cellular lobules. In B1 thymomas, immunostaining highlighted foci of medullary differentiation (7/8). B2 thymomas (n=25) were heterogeneous, with a spectrum of patterns ranging between those of B1 and B3 thymomas. Type A thymomas (n=5) mostly presented a weak positivity but one aggressive case showed zonal moderate/strong positivity. Most AB thymomas (15/17) showed weak to moderate immunostaining in spindle cell areas. In micronodular thymomas (n=3), epithelial cells and B-lymphocytes were weakly positive while follicular dendritic cells were strongly highlighted. One metaplastic thymoma displayed diffuse and moderate positivity.
Glut-1 expression globally depended on histological subtypes and the staining patterns (diffuse or zonal) were different between thymic carcinomas and type B3 thymomas. A comparative study of Glut-1 expression in atypical versus conventional type A thymomas appears warranted. Otherwise, restriction to epithelial cells makes likely a correlation with clinical assessment of glucose uptake in lymphocyte-poor tumors.
葡萄糖转运蛋白1（Glut-1）可能是鉴别B3型胸腺瘤和胸腺癌的有用标志物。鉴于相关文献有限，我们开展了一项研究，以评估其在一系列胸腺上皮肿瘤中的诊断价值。
与法国国家肿瘤学网络RYTHMIC相关的病理学家团队研究了Glut-1的表达情况。对92例连续手术标本系列中的一个石蜡块进行全切片免疫染色。评估Glut-1表达的模式（局灶性、带状、弥漫性）和强度，并与世界卫生组织组织学亚型进行比较。
表达主要局限于上皮细胞。未成熟T淋巴细胞呈阴性。大多数胸腺癌（15/16）观察到弥漫性、中度或强染色。在B3型胸腺瘤（10/11）和与胸腺癌交界的B3型胸腺瘤（5/6）中，在远离血管和纤维间隔处观察到中度至强的带状染色。这种模式有时在大细胞小叶中形成吻合网络的外观。在B1型胸腺瘤中，免疫染色突出了髓质分化灶（7/8）。B2型胸腺瘤（n = 25）具有异质性，其模式范围介于B1型和B3型胸腺瘤之间。A型胸腺瘤（n = 5）大多呈弱阳性，但1例侵袭性病例显示带状中度/强阳性。大多数AB型胸腺瘤（15/17）在梭形细胞区域显示弱阳性至中度免疫染色。在微结节性胸腺瘤（n = 3）中，上皮细胞和B淋巴细胞呈弱阳性，而滤泡树突状细胞被强烈突出显示。1例化生胸腺瘤显示弥漫性中度阳性。
Glut-1表达总体上取决于组织学亚型，胸腺癌和B3型胸腺瘤之间的染色模式（弥漫性或带状）不同。对非典型与传统A型胸腺瘤中Glut-1表达进行比较研究似乎是必要的。否则，局限于上皮细胞可能与淋巴细胞稀少肿瘤中葡萄糖摄取的临床评估相关。
