E. Tolnay et al., EXPRESSION AND LOCALIZATION OF THROMBOMODULIN IN PRENEOPLASTIC BRONCHIAL LESIONS AND IN LUNG-CANCER, Virchows Archiv, 430(3), 1997, pp. 209-212
Thrombomodulin (TM) is an endothelial surface glycoprotein that acts a
s a natural anticoagulant. It inhibits thrombin and accelerates the ac
tivation of the anticoagulant protein C. TM has been detected in derma
l keratinocytes, where it is associated with terminal differentiation.
It can also be detected in various types of squamous malignant neopla
sms and in malignancies of endothelial and mesothelial origin, such as
Kaposi's sarcoma or malignant mesothelioma, but is absent in pulmonar
y adenocarcinomas (AC). Seventy-two lung tumour specimens [33 squamous
cell carcinomas (SQCC), 23 AC, 1 large cell carcinoma, 8 small cell l
ung cancers (SCLC) and 7 multidifferentiated tumours (MT)] were analys
ed immunohistochemically by staining with an anti-TM antibody in order
to assess TM expression. All of the SQCC stained positively for TM. I
II contrast, only 9 AC and 4 MT and none of the SCLC showed positive a
nti-TM staining. Seven hyperplastic bronchial epithelial specimens and
eight preneoplastic bronchial lesions (five cases of moderate dysplas
ia, two cases of severe dysplasia and one case of carcinoma in situ) w
ere used as controls. Normal or hyperplastic areas of bronchial epithe
lium revealed no positive reaction. However, a distinct positive anti-
TM staining pattern related to the degree of keratiniziation of dyspla
stic lesions was seen. The present results suggest that anti-TM immuno
staining is a useful marker for squamous cell carcinoma in the differe
ntial diagnosis of pulmonary carcinoma, also indicating keratinocyte d
ifferentiation in dysplastic bronchial epithelium.