Figure 1
Representative Rb (a–d), p16 (e–h), cyclin D1 (i–l), cyclin B1 (m–p) and Ki-67 (q–t) immunostaining results. Nuclear Rb staining and p16 staining in most tumor cells of typical carcinoid (a, e) and atypical carcinoid (b, f), and completely absent Rb staining or p16 staining in the tumor cells of large-cell neuroendocrine carcinoma (c, g) and small-cell carcinoma (d, h), and note the positive staining in the stromal fibroblasts (arrow). Representative nuclear staining of cyclin D1 in typical carcinoid (i), atypical carcinoid (j), large-cell neuroendocrine carcinoma (k) and small-cell carcinoma (l). There are many more cyclin B1-stained cells and Ki-67-labeled cells in large-cell neuroendocrine carcinoma (o, s) and small-cell carcinoma (p, t) than in typical carcinoid (m, q) and atypical carcinoid (n, r), as well as in atypical carcinoid than in typical carcinoid. Although there are generally more Ki-67-labeled cells than cyclin B1-stained cells in individual tumors, note the general tendency of a parallel between cyclin B1-postive cells (m–p) and Ki-67-labeled cells (q–t) in number and distribution on consecutive sections.
