Quantitation of nuclear shape in non-Hodgkin's lymphoma. Alternate shape descriptors

The nuclear contour index (NCI) has been used extensively to quantitate cellular shape in non-Hodgkin's lymphoma (NHL). This disease entity has a mixed cellular component, with nuclei exhibiting a spectrum of shapes; the main disadvantage of conventional shape descriptors, such as NCI, is that similar values are assigned to these widely divergent shapes. In this study, two alternative shape indices, measures of convexity-concavity (C-C) and slimness (SL), were assessed to determine their suitability as shape descriptors. To achieve this, the contours of lymphoid cells in cytologic preparations of NHL were quantitated by means of semiautomated image analysis. C-C was able to identify nuclear clefts, with the values obtained by this index reflecting the number and depth of invaginations present; this index was unaffected by ellipsoid shapes. SL was able to describe ellipsoid profiles, irrespective of the presence of nuclear clefts; the index also characterized indentations, although precise identification of this form of invagination was difficult. This study confirms the usefulness of these indices in the characterization of nuclear shape; utilization of these shape descriptors enhances the accuracy of more-objective approaches to the morphologic classification of lymphoid lesions.