Table 1

Study definition of nuclear atypia of junctional melanocytes, adapted from groups of Weinstock et al and Rhodes and colleagues^21,²²

Feature	Normal	Minimal	Moderate	Severe
*Size of melanocyte nucleus compared with the size of basal keratinocyte nucleus (kn).
Nuclear size*	<kn	>kn	2×kn	>2×kn
Nuclear variability	Minimal	Some	Moderate	Severe
Chromatin	Homogenous/evenly dispersed, delicate	Hyperchromatic	Hyperchromatic/coarsely clumped/irregularity in nuclear contour (thickened or grooved nuclear membrane)	Hyperchromatic/coarsely clumped/irregularity in nuclear contour
Nucleolus	Not visible	Not prominent	Visible	Prominent and lavender in colour
Amount of cytoplasm	Scant	Scant	Abundant	Abundant