浆膜腔积液转移性肺腺癌细胞中TTF-1的表达

目的 探讨甲状腺转录因子-1(TTF-1)在浆膜腔积液肺腺癌细胞中的表达，为肺腺癌的诊断和鉴别诊断提供新的依据。方法 选用浆膜腔积液转移性腺癌共60例(胸水40例，腹水17例，心包积液3例)。经组织学或结合临床资料证实的肺腺癌36例，泌尿生殖道腺癌14例，胃肠道腺癌8例，乳腺癌2例。每例均制备HE染色的涂片和离心沉渣经琼脂和石蜡包埋而成的细胞块，并用细胞块切片作TTF-1免疫细胞化学染色。结果 36例肺腺癌中有26例表达TTF-1，24例肺外腺癌中只有2例表达TTF-1，其敏感性为72．2％，特异性为91．7％。结论 TTF-1在浆膜腔积液肺腺癌具有较高的敏感性和特异性，在排除甲状腺癌的可能性后，TTF-1阳性表达很大程度上提示腺癌原发于肺。     

Napsin A (TA02) is a useful alternative to thyroid transcription factor-1 (TTF-1) for the identification of pulmonary adenocarcinoma cells in pleural effusions

The purpose of this study was to test napsin A as a diagnostic marker of metastatic lung adenocarcinoma in pleural effusions, and to compare its performance with TTF-1. Napsin A and TTF-1 reactivities were determined immunohistochemically on formalin-fixed paraffin embedded cell blocks from 50 pleural effusion (5 mesotheliomas, 10 mesothelial proliferations, 12 pulmonary, and 23 nonpulmonary metastases). The results were evaluated separately, and correlated to the final diagnoses. Concordant results were obtained in 48/50 cases. TTF-1 and Napsin A were positive in 8/12 and 10/12 pulmonary adenocarcinomas, respectively. Both markers were negative in 42 cases, including two lung carcinomas. Napsin reactivity was found in more than 75% of the tumor cells in 9/10 positive cases, whereas TTF-1 reactivity was seen in more than 75% of the tumor cells in 2/8 positive cases only (P < 0.05). This makes napsin A an alternative to TTF-1 in cytological diagnosis of effusions in which tumor cells may be scanty.     

TTF-1在肺腺癌中的表达及其诊断意义

目的：评价甲状腺转录因子－1（TTF－1）在鉴别肺原发性腺癌与转移性腺癌中的临床病理应用价值。方法：20例肺原发性腺癌：10例高分化，包括3例乳头状、3例腺泡状、3例混合型腺癌和1例细支气管肺泡癌；10例低分化，包括4例黏液腺癌（其中1例为印戒细胞癌）和6例混合型腺癌。另选20例的胃肠道及卵巢腺癌，免疫组化应用TTF－1抗体。结果：95％的肺原发性腺癌表达TTF－1，而胃肠道及卵巢腺癌完全不表达。结论：对于确定肺原发或转移性腺癌的病理诊断。TTF－1是一个有用的特异性抗体，特别是在体积较小的肺活检标本或原发灶不明而仅有肺内转移时。     

Napsin A Expression in Subtypes of Thyroid Tumors: Comparison with Lung Adenocarcinomas

Napsin A is widely used in the diagnosis of lung adenocarcinoma and has also been reported to be positive in cases of thyroid carcinomas. We investigated napsin A levels through immunohistochemistry on whole sections of 210 primary thyroid tumors of various subtypes and another 41 metastatic thyroid carcinomas, and compared these with 125 primary and 25 metastatic lung adenocarcinomas. The results showed that napsin A was expressed in 23.8% thyroid tumors and 30.3% papillary thyroid carcinomas. Most cases showed a focal and weak to moderate expression. In comparison, 80.8% primary lung adenocarcinomas expressed napsin A, with mostly diffused and strong expression. For metastatic carcinomas of thyroid and lung origin, napsin A was detected in 39.0% of thyroid carcinomas in contrast to 88.0% in cases of lung adenocarcinomas. Comparisons of additional markers, TTF-1, CK7, thyroglobulin, and Pax-8 in metastatic carcinomas showed the overlapping expression of immunomarkers of TTF-1 and CK7. Thyroglobulin and Pax-8 were useful for distinguishing between metastatic carcinomas; however, Pax-8 may be a superior marker due to its higher sensitivity. The clinicopathological analysis of papillary thyroid carcinomas showed that the expression of napsin A was positively correlated with lymph node metastasis (p = 0.030). Here, we focused on the expression of napsin A in thyroid tumors and compared it with that in lung adenocarcinomas. The expression of napsin A is common in thyroid tumors and the combined expression of napsin A and TTF-1 in a metastatic thyroid carcinoma is a cause for concern due to chances of misdiagnosis as lung adenocarcinoma.

     

Value of mesothelin immunostaining in the diagnosis of mesothelioma.

Mesothelin is a cell surface antigen of unknown function that is strongly expressed in mesothelial cells. Although it was reported in 1992 that immunostaining with the K1 anti-mesothelin antibody could be very useful in distinguishing between epithelioid mesotheliomas and pulmonary adenocarcinomas, no further studies have been published on the value of this marker in the diagnosis of mesotheliomas. To determine whether mesothelin can assist in discriminating epithelioid mesotheliomas from lung adenocarcinomas or from other carcinomas metastatic to the serosal membranes, 55 mesotheliomas (44 epithelioid, 3 biphasic, and 8 sarcomatoid), 48 carcinomas of the lung (31 adenocarcinomas, 17 squamous carcinomas), and 86 nonpulmonary adenocarcinomas (14 ovary, 5 peritoneum, 9 endometrium, 11 pancreas, 4 stomach, 16 colon, 12 breast, 9 kidney, 4 thyroid, and 2 prostate) were investigated for mesothelin expression using the recently available 5B2 anti-mesothelin monoclonal antibody. Reactivity was obtained in all 44 (100%) of the epithelioid mesotheliomas, 12 (39%) of the lung adenocarcinomas, and 42 (49%) of the nonpulmonary adenocarcinomas (14 [100%] ovary; 5 [100%] peritoneum; 6 [67%] endometrium; 10 [91%] pancreas; 2 [50%] stomach; 5 [31%] colon; and in none [0] of the breast, kidney, thyroid, or prostate). Three (18%) of the squamous carcinomas of the lung, but none of the sarcomatoid mesotheliomas, exhibited positivity for this marker, nor was any reactivity seen in the spindle cell component of the biphasic mesotheliomas. It is concluded that despite the low specificity of mesothelin for discriminating between epithelioid mesotheliomas and adenocarcinomas, immunostaining for this marker may have some utility in those instances in which the results obtained with the standard panel of immunohistochemical markers used for the diagnosis of mesotheliomas are equivocal. Because mesothelin is a highly sensitive positive marker for epithelioid mesotheliomas, a negative staining for this marker is an indication against such a diagnosis; however, because of its limited utility, it is not recommended for inclusion in the standard panel of immunohistochemical markers used in the distinction between mesotheliomas and adenocarcinomas.