In recent years, few studies have specifically focused on only histological features in
choroid plexus tumors. We retrospectively reviewed the clinicopathologic and histological features in 37 patients with
choroid plexus tumors and correlated these with
glial fibrillary acidic protein (GFAP) expression and proliferation cell
nuclear antigen (
PCNA), p53, p21, and Rb labeling indexes, with special attention to
tumor recurrence/regrowth. The study included 24
choroid plexus papillomas (CPPs), 4 atypical
choroid plexus papillomas (ACPPs), and 9 choroid plexus
carcinomas (CPCs). Patient age ranged from 15 to 70 years (mean 44 years). Most of the
choroid plexus tumors were located in the IV ventricle. Recurrence was observed in 21 (52%) cases, 14 of which were
CPP and 7 of which were
CPC (P = 0.032). Histologic findings included major
necrosis,
fibrosis and psammoma bodies,
amyloid deposits,
inflammation, and thick vessels in recurrent
tumors. The
PCNA labeling index was 52.04 + or - 13.92 in CPPs, 76.50 + or - 17 in ACPPs, and 95.22 + or - 21.34 in CPCs (P = 0.009), and 67.43 + or - 28 in recurrent
tumors. Similar values were found for p53, p21, and Rb. Furthermore, we observed that these presented more histological changes, adding, than nonrecurrent
tumors, as well as a higher proliferation index of cell-cycle markers, and these were dependent predictor factors of survival. Recurrent
tumors showed a different
biological behavior than nonrecurrent
tumors, but histological observations showed no mitotic features in order to consider them as grade II.