[Immunohistochemical and immunoelectron microscopic observation of human lung carcinomas using biotinized peanut lectin (PNA)].

Ninety-three cases of various types of human primary lung carcinomas have been studied by immunohistochemical technique and 5 cases of human primary lung adenocarcinomas by immunoelectron microscopic method with biotinized peanut lectin (PNA). The results showed that PNA staining was weak positive or negative in the normal bronchial epithelial cells which are adjacent to the carcinoma studied but strong or moderate positive in the carcinoma proper (P less than 0.05). The total positive rate of the lung carcinoma in this series is 81%. About 85% of the positive adenocarcinoma the PNA receptors were distributed along the luminal border, which corresponded with the linear electron-dense deposits on the luminal surface of the adenocarcinoma cell's membrane by immunoelectron microscopy. Squamous cell carcinoma, large cell carcinoma and small cell carcinoma, large cell carcinoma and small cell carcinoma were dominant in PNA cytoplasmic positive, while clear cell carcinoma in whole cell membrane positive. Some of the squamous cell carcinoma, large and small cell carcinoma showed microlumen by PNA staining that could not be found easily by conventional HE staining. It is suggested that these carcinomas mentioned above were poorly-differentiated adenocarcinoma or other types of carcinomas combined with adenocarcinoma. The results also assumed that the increasing of PNA receptor may be proportional to the differentiation of lung carcinoma cell. Therefore PNA receptor may be considered as a marker of carcinoma cell differentiation. It could be helpful in early diagnosis of lung carcinoma and prediction of the prognosis.