Comparison of proliferation rates assessed using "multiblock" and conventional tissue blocks of lung carcinoma.
OBJECTIVE
To compare the proliferative rates, assessed immunohistochemically, of human lung tumours using conventional paraffin wax blocks and the multitumour tissue block (MTTB) technique.


METHODS
A multiblock containing 20 lung tumours (eight adenocarcinomas, five squamous cell, five small cell and two carcinoid tumours) was constructed. Sections were also cut from the original blocks of formalin fixed, paraffin wax embedded tissue used to construct the multiblock. Sections were stained with the monoclonal antibody PC10, which recognises a proliferating cell nuclear antigen, using the three stage immunoperoxidase technique.


RESULTS
The proliferation rates of the lung tumours obtained using both techniques were, overall, significantly different (p = 0.05), although most cases showed good correlation. Some tumours displayed a high degree of intratumoral variation in PC10 staining. The degree of PC10 staining was in keeping with the known proliferative state of particular histological subtypes--that is, carcinoid tumours showed little staining and small cell carcinomas showed extensive positivity.


CONCLUSIONS
The MTTB technique is a less suitable means of assessing proliferation rate in lung carcinomas than conventional tissue blocks. It should be restricted to qualitative antibody studies or quantitative studies using tumours with little intratumoral variation.
Nuffield Department of Pathology, John Radcliffe Hospital, Headington, Oxford.
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Brown
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Gatter
D000230:Adenocarcinoma / Q000473:pathology; D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm / Q000032:analysis; D002276:Carcinoid Tumor / Q000473:pathology; D018288:Carcinoma, Small Cell / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000473:pathology; D002455:Cell Division; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology*; D009687:Nuclear Proteins / Q000032:analysis; D016612:Paraffin Embedding / Q000379:methods*; D018809:Proliferating Cell Nuclear Antigen
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D009687:Nuclear Proteins; D018809:Proliferating Cell Nuclear Antigen