Shen Qin, Rao Qiu, Yu Bo, Xia Qiu-Yuan, Bao Wei, Lu Zhen-Feng, Shi Qun-Li, Zhou Xiao-Jun
Department of Pathology, Jinling Hospital, Nanjing University School of Medicine / Nanjing General Hospital of Nanjing Military Region, Nanjing, Jiangsu 210002, China.
Zhonghua Nan Ke Xue. 2016 Aug;22(8):692-697.
To study the pathological morphology, immunohistochemical characteristics, and molecular changes of type Ⅱ testicular germ cell tumors (TGCT) and investigate the possible value of immunohistochemistry and fluorescence in situ hybridization (FISH) in the diagnosis of TGCT.
We collected for this study 97 cases of TGCT, including 75 cases of seminoma, 17 cases of embryonal carcinoma, 11 cases of yolk sac tumor, 16 cases of mature teratoma, 3 cases of immature teratoma, and 1 case of epidermoid cyst, in which normal testicular tissue was found in 20 and non-TGCT in 6. We detected the expressions of different antibodies in various subtypes of TGCT by immunohistochemistry and determined the rate of chromosome 12p abnormality using FISH.
The immunophenotypes varied with different subtypes of TGCT. SALL4 and PLAP exhibited high sensitivity in all histological subtypes. CD117 and OCT4 showed strongly positive expressions in invasive seminoma and germ cell neoplasia in situ (GCNIS) but not in normal seminiferous tubules. GPC3 was significantly expressed in the yolk sac tumor, superior to GATA3 and AFP in both range and intensity. CKpan, OCT4, and CD30 were extensively expressed in embryonal carcinoma, while HCG expressed in choriocarcinoma. The positivity rate of isochromosome 12p and 12p amplification in TGCT was 96.7% (29/30).
The majority of TGCT can be diagnosed by histological observation, but immunohistochemical staining is crucial for more accurate subtypes and valuable for selection of individualized treatment options and evaluation of prognosis. Chromosome 12p abnormality is a specific molecular alteration in type Ⅱ TGCT, which is useful for ruling out other lesions.
研究Ⅱ型睾丸生殖细胞肿瘤（TGCT）的病理形态、免疫组化特征及分子改变，探讨免疫组化和荧光原位杂交（FISH）在TGCT诊断中的可能价值。
本研究收集了97例TGCT，包括75例精原细胞瘤、17例胚胎癌、11例卵黄囊瘤、16例成熟畸胎瘤、3例未成熟畸胎瘤和1例表皮样囊肿，其中20例有正常睾丸组织，6例为非TGCT。通过免疫组化检测TGCT各亚型中不同抗体的表达，并使用FISH测定12号染色体p臂异常率。
TGCT不同亚型的免疫表型各异。SALL4和PLAP在所有组织学亚型中均表现出高敏感性。CD117和OCT4在浸润性精原细胞瘤和原位生殖细胞肿瘤（GCNIS）中呈强阳性表达，但在正常生精小管中不表达。GPC3在卵黄囊瘤中显著表达，在范围和强度上均优于GATA3和AFP。CKpan、OCT4和CD30在胚胎癌中广泛表达，而HCG在绒毛膜癌中表达。TGCT中12号染色体等臂和12号染色体p臂扩增的阳性率为96.7%（29/30）。
大多数TGCT可通过组织学观察诊断，但免疫组化染色对于更准确的亚型诊断至关重要，对选择个体化治疗方案和评估预后有重要价值。12号染色体p臂异常是Ⅱ型TGCT的特异性分子改变，有助于排除其他病变。
