Cellular morphometry in nongynecologic thin-layer and filter cytologic specimens

To determine the feasibility and utility of thin-layer cytology preparations for morphometric analysis of nuclear and cytoplasmic area in cells from nongynecologic cytology specimens.

Identical paired samples from nongynecologic specimens (bronchial aspirate, urine, pleural and peritoneal fluid) were used to prepare thin-layer preparations and corresponding traditional membrane filter preparations. The paired preparations were analyzed by static image morphometry measuring eight nuclear and cytoplasmic parameters that allowed calculation of nuclear area, cytoplasmic area and total cell size. Hepatocytes and bronchial columnar, mesothelial, squamous and transitional cells were studied, as was a single case of high grade transitional cell carcinoma. Sufficient numbers of each cell type were measured to allow statistical analysis.

Both thin-layer and membrane filter preparation techniques yielded individual cells suitable for morphometric analysis, and there were no consistent morphologic measurement differences between the two methods. The thin-layer preparation had the following significant technical advantages: more numerous easily measured single cells, lack of interfering background and superior specimen stability. Benign oval to round nuclei from a variety of cell types have a mean nuclear area in a narrow range from 29 to 55 microns 2. The mean nuclear area of malignant cells studied was significantly larger (78 microns 2), and there was a significant decrease in absolute cytoplasmic profile area in the malignant population studied.

Thin-layer cytology preparations have significant advantages for morphometric studies over traditional membrane filter cytologic preparations. The morphometric measurement of nuclear area in benign and malignant cell populations has great potential as a generic screening tool for malignancy in cytologic specimens. Simultaneous measurement of cytoplasmic area adds a powerful dimension. The subsequent calculation of a true nuclear/cytoplasmic ratio may yield a sensitive and specific discriminator for detecting malignant cell populations in human nongynecologic cytology specimens.