A technique to improve diagnostic information from fine-needle aspirations: immunohistochemistry on cytoscrape.
BACKGROUND
Cytologic examination of fine-needle aspiration (FNA) material is being used increasingly for the diagnosis of pulmonary lesions. Accurate distinction between nonsmall cell lung cancer (NSCLC), including subgroups, and small cell lung cancer and between primary lung cancer and metastases has therapeutic impact. However, the distinction between these groups may be difficult on smears. In this report, the authors describe a simple method, called cytoscrape (CS), which can be used on virtually any smear to produce material useful for ancillary methods, including immunohistochemistry.


METHODS
Aspirates from 47 patients who had possible malignant infiltrates identified on computed tomography scans of the chest were included. Smears were stained by May-Grunwald-Giemsa and Diff-Quick for diagnostic purposes. CS material was obtained by gently scraping cells off the slides. Clots were made, and the sections were stained for thyroid transcription factor-1 (TTF-1) and mucin. The utility of the CS technique was evaluated by assessing the sensitivity and specificity of the method and by quantifying the extra diagnostic information obtained by the method relative to smears alone.


RESULTS
Malignant tumor cells in the CS material were identified in 43 aspirates (91%). Both the sensitivity and the specificity for TTF-1 were 100%. The sensitivity for mucin was 60%, and the specificity for mucin was 100%. The diagnoses made on smears were improved by CS in 31 patients (72%), in that more precise separation of subgroups of NSCLC was possible or information on primary tumors was obtained.


CONCLUSIONS
The CS technique improved the diagnostic information from FNA in a clinically relevant way. The method is simple, quick, and inexpensive.
Department of Pathology, Herlev University Hospital, Division Gentofte, Copenhagen, Denmark. bigu@heh.regionh.dk
Birgit Guldhammer
BG
Skov
Katalin
K
Kiss
Julie
J
Ramsted
Dorte
D
Linnemann
D044963:Biopsy, Fine-Needle; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism / Q000473:pathology*; D003581:Cytodiagnosis / Q000379:methods; D003937:Diagnosis, Differential; D006801:Humans; D007150:Immunohistochemistry; D008168:Lung / Q000737:chemistry / Q000473:pathology*; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology*; D009077:Mucins / Q000032:analysis; D009362:Neoplasm Metastasis; D009687:Nuclear Proteins / Q000032:analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055752:Small Cell Lung Carcinoma / Q000378:metabolism / Q000473:pathology*; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000032:analysis
D009077:Mucins; C000614412:NKX2-1 protein, human; D009687:Nuclear Proteins; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors