Kung I T, Thallas V, Spencer E J, Wilson S M
Department of Anatomical Pathology, Heidelberg Repatriation Hospital, Victoria, Australia.
Hum Pathol. 1995 May;26(5):565-70. doi: 10.1016/0046-8177(95)90254-6.
Ultrastructural examinations have shown myofibroblastoid differentiation in sarcomatoid/desmoplastic mesotheliomas, but immunohistochemical expression of muscle actins seldom has been documented. We examined 10 sarcomatoid, 12 epithelial, and five biphasic mesotheliomas immunohistochemically for the expression of muscle-specific actin (MSA) and smooth muscle actin (SMA) and compared it with that in 12 specimens of lung cancer. All of the sarcomatoid mesotheliomas were found to be positive for both MSA and SMA. The epithelial cells in nine epithelial and two biphasic mesotheliomas were positive for MSA, but SMA was only positive in one epithelial mesothelioma. Conversely, the lung cancers were negative for both MSA and SMA in the epithelial cells, except for one specimen that was weakly positive for MSA. The stromal cells in both the epithelial mesotheliomas and lung cancers were negative for cytokeratin but were positive for MSA and SMA, whereas the sarcomatoid and biphasic mesothelioma spindle cells were positive for all three antibodies. We concluded that sarcomatoid mesothelioma was positive for MSA and SMA, which is in support of its myofibroblastic differentiation, and that positivity for MSA in some epithelial mesotheliomas might be of diagnostic value in differentiation from lung cancers.
超微结构检查显示肉瘤样/促纤维组织增生性间皮瘤中有肌成纤维细胞样分化，但肌肉肌动蛋白的免疫组化表达鲜有记录。我们对10例肉瘤样、12例上皮样和5例双向性间皮瘤进行了肌肉特异性肌动蛋白（MSA）和平滑肌肌动蛋白（SMA）免疫组化表达检测，并与12例肺癌标本进行比较。所有肉瘤样间皮瘤的MSA和SMA均呈阳性。9例上皮样和2例双向性间皮瘤的上皮细胞MSA呈阳性，但仅1例上皮样间皮瘤的SMA呈阳性。相反，肺癌上皮细胞的MSA和SMA均为阴性，仅1例标本MSA呈弱阳性。上皮样间皮瘤和肺癌的基质细胞细胞角蛋白呈阴性，但MSA和SMA呈阳性，而肉瘤样和双向性间皮瘤的梭形细胞三种抗体均呈阳性。我们得出结论，肉瘤样间皮瘤的MSA和SMA呈阳性，支持其肌成纤维细胞分化，一些上皮样间皮瘤MSA阳性可能对与肺癌的鉴别诊断有价值。
