Ultrastructural studies of malignant cells in fluids

Abstract
An ultrastructural study was performed on 104 sequential fluids in which more than eight malignant cells per ten highpower fields were found by routine light microscopy. The study included fluids associated with mesotheliomas, melanomas, lymphomas, squamous-cell carcinomas, small-cell anaplastic (oat-cell) carcinomas, and adenocarcinomas. Electron microscopic examination reliably separated lymphoid from epithelial malignancies and benign from reactive and malignant mesothelial cell proliferations. It also suggested or identified a primary site for the adenocarcinomas. Ultrastructural examination of fluids can be a valuable adjunct to routine light microscopy of cytology specimens. No false-positive diagnoses were encountered. Sampling was the most significant limitation for this technique.