Figure 2.

Supernumerary centrioles in breast tumors. A: A procentriole (arrow) is present at the proximal end of one of the two centrioles in this section. This procentriole is identifiable by its orthogonal orientation relative to the full length centriole and by the width of its lumen. Notice the electron opaque pericentriolar satellites surrounding the centrioles. B: Two centrioles are seen in cross section and a third is in longitudinal section. One centriole has subdistal appendages (arrow). All three are close to the nucleus (N). There is no orthogonal relationship between any of the three centrioles. C: At least two of these four centrioles have subdistal appendages (arrows). D: The barrels of these five centrioles are coated with a fine electron opaque material. Two centrioles have distal appendages (arrows) and at least one also has subdistal appendages (arrowhead). E: This group of six centrioles is linked by fine fibers between their subdistal appendages (arrows). The group is next to the nucleus (N). F: At least nine centriole profiles are present in this thin section. Subdistal (arrows) and distal (arrowhead) appendages are seen on many of the centrioles. The nucleus (N) is adjacent to this cluster of centrioles. Original magnifications, ×27,500 (A and B), ×32,300 (C and F), ×31,000 (D), ×34,150 (E).