There were no statistically significant differences in rates of RB positivity between the primary and recurrent tumor groups, although the H-score was higher in the latter (Table 2).Ki-67 is a marker for proliferating cells in neoplastic lesions; the Ki-67 LI was found to be in the range of 0–12.4% for moderate immunoreactivity (2+), with mean values of 2.76 and 4.09% for primary and recurrent groups, respectively. Here, RB1 is linked to neoplasm.