Pattern of fibronectin distribution in human lung cancer.

The pattern of fibronectin (FN) distribution in human lung cancer was studied by indirect immunofluorescent staining, and by the peroxidase-antiperoxidase method in a total of 60 surgical specimens. They comprised 8 small cell carcinomas, 4 large cell carcinomas, 19 squamous cell carcinomas, 28 adenocarcinomas, and 1 adenoid cystic carcinoma. Of the 60 specimens 13 were FN-positive. They included 4 large cell carcinomas, 4 small cell carcinomas, 3 poorly differentiated squamous cell carcinomas, and 2 poorly differentiated and 1 moderately differentiated adenocarcinomas. On the other hand, none of the well differentiated carcinomas was FN-positive around tumor cells. Our data suggest that undifferentiated, or poorly differentiated carcinomas of the lung tend to be FN-positive.