Overlap in primary presenting features among leukemic T-cell tumors and secondary features that assist in more definitive classification. The number of overlapping cases is given in the convex, shaded areas between the overlapping circles, with each overlap case manifesting the primary feature from both categories. Indicated are the primary (no. 1) as well as secondary features (nos. 2 and 3) identified in this study that correspond to particular WHO diagnostic categories. Abbreviations are explained in the legend to Figure 1.