The expression of trophoblastic cell markers by lung carcinomas

The authors studied the expression of trophoblastic cell markers in lung carcinomas cells by immunoperoxidase staining using antibodies against three trophoblastic glycoproteins (human chorionic gonadotropin [hCG]; human placental lactogen [hPL]; pregnancy-specific beta 1-glycoprotein [SP-1]). One hundred five tissue sections from 44 lung carcinomas of various histological types were examined for positive staining with three antibodies. Hematoxylin-eosin-stained sections from the same tissue blocks were examined for the presence of tumor giant cells. The aim was to study the relationship between tumor giant cells and the trophoblastic glycoprotein expression in lung carcinomas. Small cell carcinoma (SCC) did not show any positive reaction with all three markers. Squamous cell carcinoma (SQCC) showed positive staining with hCG in 21% of cases, hPL in 28%, and SP-1 in 64%. Adenocarcinoma showed positive staining with hCG in 60% of cases, hPL in 10%, and SP-1 in 80%. Large cell carcinoma (LCC) showed positive staining with hCG in 93% of cases, hPL in 56%, and SP-1 in 93%. The positive reaction did not appear to be restricted to nor associated with the tumor giant cells. It was concluded that these trophoblastic cell markers are expressed in various types of lung carcinomas and that they are not associated with certain histological types or with tumor giant cells.