For all 325 images of pigmented lesions with globules from these image sets, students (J.X., Y.K., A.B., and D.C.) and a dermatologist (W.V.S.) identified globules and variant globulelike structures. These globules and variant structures were identified as 1 of the following 6 types (Figure 1): (a) classical (dark [heavily pigmented], discrete globules with convex shape, 0.10-0.20 mm), (b) large (dark, discrete globules of varying shape, 0.20-0.70 mm), (c) irregular (dark, discrete globules with irregular nonconvex shape, 0.10-0.20 mm), (d) light (discrete convex globules with light coloring, 0.05-0.70 mm), (e) small dot-globule variant (dark, discrete globules, 0.03-0.05 mm), or (f) connect-globule variant (dark, nondiscrete globules connected to a pigment network or a blotch, 0.05-0.20 mm). The classical globule sizes were classified as 0.03 to 0.05 mm, 0.05 to 0.10 mm, and 0.10 to 0.20 mm in diameter. Globule size was measured as the greatest diameter, determined using the known ×10 magnification of the images. We did not attempt to separate black globules from brown globules, as is sometimes done in the literature, because we found that few globules have pigmentation so dark as to be considered black and because such cases appear against a dark background. Globule size for each optical platform was calibrated using images that contained ruler scales within the images. Using these images with ruler scales and the known resolution of the images in pixels, we determined the upper and lower limits of pixel diameter for each category of globule size. For example, fully zoomed images (DermLite Fluid) from the clinics were calibrated at 0.01 mm per pixel; images that were not fully zoomed were calibrated by the scale visible on the images. Other images (Dermaphot) from the atlas were calibrated at 0.0125 mm per pixel. In the past, globule shape has been defined as round or oval, but globules of pigmented lesions commonly have a blob shape such as an imperfect egg shape or rounded trapezoid shape, as shown in Figures 2, 3, 4, 5, and 6 (the green globules are considered of regular shape). Therefore, regular globule shape was assigned only if the globule outline was rounded and generally convex. Otherwise, globules were classified as irregular. Elongation was the most common characteristic of irregular globules in our set of lesions. Other globule types are defined in Figure 1. Figures 2 through 6 show examples of the different globule types in benign and malignant nevocellular lesions. The presence or absence of each globule type was recorded in a database.