摘要目的：探讨三种鳞癌标志物（ p63、p40、CK5／6）及神经内分泌标志物[嗜铬粒素 A （ CgA）、突触素、CD56]、甲状腺转录因子（ TTF）-1在小细胞肺癌中的表达及其在鉴别诊断中的价值。方法收集283例小细胞肺癌的免疫组织化学结果，分析p63、p40、CK5／6、CgA、突触素、CD56及TTF-1等7种抗体的表达情况。结果小细胞肺癌中 p63、p40、CK5／6的阳性率分别为20.7％（54／261）、7.9％（5／63）、0.5％（1／221），三者的阳性率差异有统计学意义（χ2＝51.05，P＜0.01）。神经内分泌标志物CgA、突触素、CD56的阳性率分别为61.8％（170／275）、85.5％（242／283）、89.2％（248／278），三者的阳性率差异有统计学意义（χ2＝73.50，P ＜0.01）。 TTF-1的阳性率为77.2％（217／281）。结论 p63、p40在部分小细胞肺癌病例表达，CK5／6的表达率很低。神经内分泌标志物突触素、CD56在小细胞肺癌中敏感性高于CgA。 CK5／6、突触素、CD56在小细胞肺癌与低分化鳞癌的鉴别诊断中有较高的实用价值。

abstractsObjective To study the expression of squamous cell markers p63, p40 and CK5/6 in small cell carcinoma of lung ( SCLC ).Methods Immunohistochemical study for squamous cell markers (p63, p40 and CK5/6), neuroendocrine markers (chromogranin A, synaptophysin and CD56) and TTF1 was carried out in 283 cases of SCLC.The diagnostic value of these markers was evaluated.Results The expression rate of p63, p40 and CK5/6 were 20.7% (54/261), 7.9% (5/63) and 0.5% (1/221), respectively in the cases of SCLC studied.Amongst the squamous cell markers, CK5/6 had the lowest rate of positivity ( P <0.01 ).On the other hand, chromogranin A, synaptophysin and CD56 were positive in 61.8%( 170/275 ) , 85.5% ( 242/283 ) and 89.2% ( 248/278 ) , respectively.The positivity rate for chromogranin A was lower than that for synaptophysin and CD56 ( P <0.01 ).TTF1 was expressed in 77.2%(217/281).Conclusions p63 and p40 are expressed in a subset of SCLC.In contrast, CK5/6 is rarely positive in SCLC.An immunohistochemical panel of CK5/6, synaptophysin and CD56 is recommended for differential diagnosis of SCLC.