The diagnosis of cancer from body fluids. A comparison of cytology, DNA measurement, tissue culture, scanning and transmission microscopy.

A consecutive series of 70 exudates from 45 patients with clinically suspected malignancy was examined by cytology, cytophotometric measurement of DNA, short-term cell culture, scanning and transmission electron microscopy. In seven patients (21 fluids), the presence of malignant disease was verified. Malignant and benign cases were correctly diagnosed by combination of cytology and DNA analyses. An abnormal DNA profile defined by greater than 10 per cent cells with greater than 2c DNA or single cells with greater than 8c DNA was only seen in malignant exudates. Short-term cell culture with scanning electron microscopy could distinguish between lymphoid cells, histiocytes, fibroblasts, mesothelial cells and cancer cells. Only cancer cells had prominent microvilli on their surface. A future larger series will explore whether a combination of cytology and cytophotometric DNA estimation alone will improve the diagnostic accuracy to the same substantial degree as this pilot study would suggest.