Pulmonary surfactant contains a number of proteins including the 10 kD Clara cell protein and surfactant proteins A, B, C and D. As markers of primary pulmonary adenocarcinoma, they are inferior to TTF-1.
Surfactant apoprotein A appears to be a major constituent of giant lamellar bodies.
PE-10 is a monoclonal antibody against components of human surfactant proteins4. Staining may be a combination of cytoplasmic and nuclear inclusions12. It is said to have high specificity for adenocarcinoma of the lung when compared to the results obtained with polyclonal antibodies5.
Immunoreactivity
|
PE-10 |
Sp-A |
Sp-B |
TTF-1 |
|
primary lung tumours |
adenocarcinoma |
6/164, 18/7512, 13/2113 |
25/461 |
29/461, 52%6, 119/20911 |
35/461, 158/20911 |
squamous cell carcinoma |
0/84, 0/512 |
2/101 |
0/101, 0/10111 |
0/101, 0/10111 |
|
adenosquamous carcinoma |
|
1/11 |
1/11 |
1/11 |
|
small cell carcinoma |
0/54, 0/112 |
|
|
|
|
large cell carcinoma |
0/64, 0/812 |
|
12/6111 |
16/6111 |
|
pleomorphic carcinoma |
|
|
|
||
Malignant mesothelioma |
0/913 |
|
0/9511 |
0/9511 |
|
primary breast carcinoma |
|
4/511 |
0/511 |
0/511 |
|
breast carcinoma metastatic to lung |
1/64 |
6/131 |
6/131 |
0/131 |
|
carcinoma metastatic to lung |
1/144 |
|
|
|
|
Papilllary and bronchoalveolar carcinoma of the lung may show apparent nuclear positivity, which is attributable to the presence of nuclear inclusions containing material with the antigenicity of surfactant A7. Such nuclear inclusions have been shown to co-express TTF-17.
It appears that breast tumour cells metastatic to the lung incorporate pulmonary surfactant proteins, which are therefore of little value if differentiating metastatic breast carcinoma from primary pulmonary adenocarcinoma1.
The pattern of staining for surfactant A is different in primary pulmonary adenocarcinoma and mesothelioma, but there are many more informative antibodies.
|
adenocarcinoma |
mesothelioma |
Surfactant A |
35/35 (9 membranous, 26 cytoplasmic)3 |
40/41 (33 membranous, 7 cytoplasmic)3 |
Surfactant B |
6/2410 |
2/1310 |
Diagnostic utility
Surfactant is exclusively produced by the lung such that one might expect it to provide be a good lung-specific marker. However, this does not appear to be the case. Although displaying some specificity for lung and lung tumors, antibodies to surfactants used for immunohistochemistry lack sensitivity and specificity. According to some authors, only 63% of primary lung carcinomas stain with surfactant protein A and B while 46% of metastatic carcinomas, including primary breast cancers, stain with surfactant A and B antibodies9.
References
4 Chhieng DC, Cangiarella JF, Zakowski MF, et al. Use of thyroid transcription factor 1, PE-10, and cytokeratins 7 and 20 in discriminating between primary lung carcinomas and metastatic lesions in fine-needle aspiration biopsy specimens. Cancer 2001; 93:330-6 FULL TEXT
9 Jagirdar J. Application of immunohistochemistry to the diagnosis of primary and metastatic carcinoma to the lung. Arch Pathol Lab Med 2008; 132:384-96 FULL TEXT
*** to be done ***
This page last revised 21.11.2008.
©SMUHT/PW Bishop