HISTOCHEMICAL REACTIVITIES OF LECTINS AND SURFACTANT APOPROTEIN IN PULMONARY ADENOCARCINOMAS AND THEIR METASTASES

In an attempt to better understand the biologic behavior of neoplastic cell metastasis, a histochemical study with the use of six different lectins and a monoclonal antibody against human pulmonary surfactant apoprotein (PE-10) was carried out on primary adenocarcinomas of the lungs and their regional (usually lymphatic to lymph nodes or contralateral lung) and distant (usually hematogenous to extrathoracic organs) metastatic lesions of 54 postmortem cases. Primary pulmonary adenocarcinomas were classified further into acinar, papillary, and solid types according to WHO histological typing. Acinar type primary adenocarcinoma of the lungs showed significantly higher (p < 0.05) binding reactions to Ricinus communis-I (RCA-I) and Ulex europaeus-I (UEA-I) lectins than solid type adenocarcinoma. With six different lectins, concordantly positive reaction's between primary pulmonary adenocarcinomas and their lymphatic and hematogenous metastases were seen in 67% or more cases, and with soybean agglutinin (SBA) and UEA-I the concordance rates between primary and lymphatic metastases (lymph nodes and contralateral lungs, respectively) were significantly higher (p < 0.05) than those between primary and hematogenous metastases. With PE-10 immunohistochemistry, concordantly positive reactions between primary and metastases were low, especially in cases of distant hematogenous metastases (25%), but the statistical significance of differences was missed by narrow margins. With alcian blue PAS-stain, concordantly positive reactions of mucin production between primary adenocarcinomas and both lymphatic and hematogenous metastases were high (92%), but there was no evidence of correlation between lectin bindings and alcian blue-PAS reactions to either primary or metastatic lesions of pulmonary adenocarcinomas.