Although GATA3 has been recognized as a useful marker for mammary and urothelial carcinomas, there is large variation in GATA3 expression detected in pheochromocytoma (PC) and paraganglioma (PGL), from 90% to less than 5%. For GATA3 to be a useful diagnostic marker for PCCs/PGLs, the reasons for such discrepancy must be elucidated. Thus, we compared different immunohistochemistry protocols. Three protocols for GATA3 immunohistochemistry, including the use of an automated slide stainer or manual staining with an autoclave and EDTA buffer vs citric acid buffer, were compared. Whole sections of paraffin-embedded tumors, including 30 PCCs, 37 PGLs including 15 head and neck PGLs, 5 retroperitoneal PGLs, 17 urinary bladder PGLs, and 14 neuroblastoma group tumors, were examined and compared with mammary and urothelial carcinoma sections as positive controls. Using the automated slide stainer (Benchmark ULTRA; Ventana Medical Systems) with both buffers, mammary and urothelial carcinomas demonstrated strong GATA3 positivity; however, PCCs/PGLs showed negative or weak heterogeneous staining. Manual staining with an autoclave for antigen retrieval resulted in increased GATA3 immunoreactivity in all head and neck PGLs, all retroperitoneal PGLs, 88% of urinary PGLs, 17% of PCCs, and all neuroblastomas, except for ganglion cells. The normal adrenal medulla stained weakly and heterogeneously. In conclusions, immunohistochemistry for GATA3 in PCCs/PGLs requires stronger antigen retrieval than that in mammary and urinary carcinomas. This finding is especially important to consider if GATA3 is applied for the differential diagnosis of PGLs in unusual sites as supplemental data to the expression of catecholamine-synthesizing enzymes.

中文翻译：

---

GATA3免疫组织化学在嗜铬细胞瘤和副神经节瘤中的诊断难题。

尽管公认的GATA3是乳腺和尿路上皮癌的有用标志物，但在嗜铬细胞瘤（PC）和副神经节瘤（PGL）中检测到的GATA3表达存在很大的差异，从90％到小于5％。为了使GATA3成为PCC / PGL的有用诊断标记，必须阐明这种差异的原因。因此，我们比较了不同的免疫组化方案。对GATA3免疫组织化学的三种方案进行了比较，包括使用自动幻灯片染色器或高压釜和EDTA缓冲液与柠檬酸缓冲液的手动染色。石蜡包埋的肿瘤的整个切片，包括30个PCC，37个PGL，包括15个头颈部PGL，5个腹膜后PGL，17个膀胱PGL和14个成神经细胞瘤组肿瘤，检查并与乳腺和尿路上皮癌切片作阳性对照。使用带有两种缓冲液的自动玻片染色机（Benchmark ULTRA； Ventana Medical Systems），乳腺和尿路上皮癌表现出很强的GATA3阳性性。然而，PCCs / PGLs呈现阴性或弱异质染色。用高压灭菌器手工染色进行抗原修复导致所有头颈部PGL，所有腹膜后PGL，88％的尿PGL，17％的PCC和所有神经母细胞瘤（神经节细胞除外）的GATA3免疫反应性增加。正常的肾上腺髓质染色较弱且异质。总之，PCC / PGL中GATA3的免疫组织化学需要比乳腺和泌尿癌更强的抗原回收。