Skull base chordomas: correlation of tumour doubling time with age, mitosis and Ki67 proliferation index

The aim of the study was to assess the relationship between the rate of cli nical tumour growth and various histological features, including Ki67 label ling index, in skull base chordoma. Cases of skull base chordoma from 19 pa tients (six female, 13 male; age range 8-63 years) were reviewed and the di agnosis confirmed based on histological and immunohistochemical features. I n each biopsy cellularity, pleomorphism, mitotic activity, apoptotic bodies , necrosis and inflammatory cell infiltrate were graded and Ki67 labelling index (LI) calculated as a measure of proliferation. Tumour doubling time w as assessed by quantitative analysis of tumour volumes in post-operative ma gnetic resonance images and correlated with age, sex, histological paramete rs and Ki67 LI. It was shown that increasing patient age, the presence of m itotic figures or a Ki67 LI in excess of 6% were associated with faster gro wing tumours.