Basaloid squamous cell carcinoma of the esophagus: an immunohistochemical study of 8 cases

Objective To explore the biological features of basaloid squamous cell carc inoma ( BSC) of the esophagus. Methods Cytokeratins (CK4, CK18 and CK19), epithelial membrane antigen (EMA ), carcino embryo antigen (CEA), alpha -smooth muscle antigen (alpha -SMA), S-100, laminin (LN), collagen IV (Col-IV), neural-specific enolase (NSE), proliferating cell nuclear antigen (PCNA) and p53 antibodies were used to d etect the corresponding antigen expression in 8 cases of BSC with ABC immun ohistochemical methods. Results Two kinds of BSC cell components have different responses to the ab ove antibodies. For basaloid cells (BCs), 7 cases were positive for CK19, a nd were negative for the other 4 epithelial antibodies CK4, CK18, CEA and E MA. BCs of 4 cases were positive to the muscular antibodies alpha -SMA and S-100, and the hyaline degeneration in the tumor nests was positive for LN and Col-N. BCs had a high index of PCNA, with an average level of 54%. For squamous cells (SCs), 7 cases were positive for the epithelial antigen CK4, CEA and EMA, but were negative for CK19, alpha -SMA and S-100. The index o f PCNA of SC was low, with an average level of 25%. Conclusion BSC of the esophagus is a high-malignancy tumor which is of mult i-oriented differentiation. BCs represent basal cells which have the tenden cy of myoepithelial differentiation and have strong proliferation ability, whereas SCs represent typical squamous cell differentiation.