LAUSR

Abstract. We present the results of the first quantitative multimodal confocal imaging study of methylene blue (MB)-stained cancer and normal human renal cells obtained from fine needle aspiration (FNA) biopsies. Fluorescence emission images provided morphological assessment, and fluorescence polarization (Fpol) images yielded quantitative characterization of each cell in the investigated samples. FNA specimens are obtained from discarded malignant and normal renal specimens following surgery. Prior to imaging, the cells are stained in aqueous MB solution. Our results demonstrate that all the specimens investigated are heterogeneous in terms of size and exhibited Fpol. Cancerous specimens predominantly contain cells of larger size that exhibit higher Fpol as compared to normal specimens. Imaging results correlated well with clinical assessment of the samples. Our results suggest that morphological assessment using fluorescence emission imaging and quantitative information provided by Fpol imaging may be valuable in determining the presence or absence of renal cancer cells in FNA specimens.