IMMUNOHISTOCHEMICAL STAINING PATTERNS OF KERATINS IN NORMAL ESOPHAGEAL EPITHELIUM AND CARCINOMA OF THE ESOPHAGUS

To clarify the keratin staining patterns of invasive carcinoma of the oesophagus, 22 cases of formalin-fixed paraffin-embedded surgical spec imens were examined immunohistochemically with the labelled streptavid in biotin method using a panel of six different monoclonal anti-kerati n antibodies. The antibody reacted adequately when antigen was retriev ed in a microwave oven, and the relationship between morphological cha racteristics and keratin reaction patterns was analyzed in carcinomas and compared with adjacent histologically normal epithelium. In the no rmal oesophageal epithelium, AE3 and CK8.12 labelled all layer of cell s, KS-1A3, E3 and KL1 labelled suprabasal cells, and LL002 selectively labelled the basal cells. In squamous cell carcinomas, AE3, CK8.12, K L1 and LL002 labelled almost all the tumour cells regardless of their differentiation, E3 only labelled keratinized cells, while marked decr ease or loss of KS-1A3 staining was seen in all cases examined. Theref ore, the characteristic profile of squamous cell carcinoma was a stron g and diffuse expression of keratin 14 and 16, strong but localized ex pression of keratin 17, and loss of keratin 13 expression. Undifferent iated carcinoma totally lacked all keratin reactivity. The findings su ggested that the neoplastic epithelial cells showed different keratin reactivity and distribution compared to normal oesophageal epithelium. In addition, histologically normal epithelium, dysplasia and carcinom a-in-situ adjacent to or overlying carcinoma expressed keratin 14.