Beschorner Rudi, Pantazis Georgios, Jeibmann Astrid, Boy Jana, Meyermann Richard, Mittelbronn Michel, Schittenhelm Jens
Institute for Brain Research, Eberhard-Karls-University, Tübingen, Germany.
Acta Neuropathol. 2009 Jun;117(6):667-75. doi: 10.1007/s00401-009-0519-y. Epub 2009 Mar 13.
Microscopic distinction of normal choroid plexus (CP) from choroid plexus tumors (CPT) may be difficult, especially in small samples of well-differentiated CP papillomas. So far, there are no established markers that reliably distinguish normal and neoplastic CP epithelium. Recently, a correlation between expression/function of glial glutamate transporters EAAT-1 (GLAST) and EAAT-2 (Glt-1) and tumor proliferation has been reported. Furthermore, we previously found that CPTs frequently express EAAT-1, but not EAAT-2. We now compared expression of EAAT-1, EAAT-2 and GFAP in non-neoplastic CP (n = 68) and CPT (n = 79) by immunohistochemistry. Tissue of normal CP was obtained from 50 autopsy cases (20 normal and 30 pathologic brains) and 18 neurosurgical specimens that included 17 fetal, 21 pediatric and 30 adult cases. In non-neoplastic postnatal CP (n = 51), focal expression of EAAT-1 was found in only two pediatric cases (4%). In CPT, expression of EAAT-1 was found in 64 of 79 (81%) tumor samples and was significantly age-dependent (P < 0.0001). Hence, EAAT-1 expression distinguishes neoplastic from normal CP, both in children (P = 0.0032) and in adults (P < 0.0001). Immunostaining for EAAT-2 in selected samples from cases of different ages showed that normal CP (n = 15) or CPT (n = 16) lacked EAAT-2 expression. GFAP expression was found in 3 of 32 (10%) normal CP and in 28 of 73 (38%) tumor samples. In conclusion, in contrast to neoplastic CP samples, expression of EAAT-1 is exceptionally rare in non-neoplastic CP. Thus, EAAT-1 is superior to GFAP as a helpful diagnostic tool in CP samples.
在显微镜下区分正常脉络丛（CP）和脉络丛肿瘤（CPT）可能具有挑战性，尤其是在分化良好的CP乳头状瘤的小样本中。到目前为止，尚无可靠区分正常和肿瘤性CP上皮的既定标志物。最近，有报道称胶质谷氨酸转运体EAAT-1（GLAST）和EAAT-2（Glt-1）的表达/功能与肿瘤增殖之间存在关联。此外，我们之前发现CPT经常表达EAAT-1，但不表达EAAT-2。我们现在通过免疫组织化学比较了EAAT-1、EAAT-2和GFAP在非肿瘤性CP（n = 68）和CPT（n = 79）中的表达。正常CP组织取自50例尸检病例（20例正常脑和30例病理脑）以及18例神经外科标本，其中包括17例胎儿、21例儿科和30例成人病例。在非肿瘤性产后CP（n = 51）中，仅在两例儿科病例（4%）中发现EAAT-1的局灶性表达。在CPT中，79个肿瘤样本中有64个（81%）发现EAAT-1表达，且与年龄显著相关（P < 0.0001）。因此，EAAT-1表达可区分儿童（P = 0.0032）和成人（P < 0.0001）的肿瘤性CP与正常CP。对不同年龄病例的选定样本进行EAAT-2免疫染色显示，正常CP（n = 15）或CPT（n = 16）均缺乏EAAT-2表达。在32例正常CP中有3例（10%）发现GFAP表达，在73例肿瘤样本中有28例（38%）发现GFAP表达。总之，与肿瘤性CP样本相比，EAAT-1在非肿瘤性CP中的表达极为罕见。因此，在CP样本中，EAAT-1作为一种有用的诊断工具优于GFAP。
