Mitotic frequency in different early stages of testicular seminoma

The proliferation behaviour of early seminoma was studied by analysis of the mitotic frequency in defined stages of tumour development: Carcinoma in-situ, intratubular seminoma, intratubular seminoma with interstitial seminoma cells and solid seminoma. It was shown that the mitotic frequency increased during the process of tumour development and that tumour cells in different tissue compartments show a different proliferation behaviour. The first stage example (CIS) showed a mitotic frequency of 0.65% while the second stage example (intratubular seminoma) showed a mitotic frequency of 0.84%. The separated analysis of the third stage example (intratubular seminoma with interstitial seminoma cells) showed a mitotic frequency of 1.45% for the intratubular compartment and 0.72% for the interstitial compartment. The fourth stage example (solid seminoma) showed a mitotic frequency of 3.59%. The finding that mitotic frequencies differ in the examined stage examples are interpreted as an adaptation process of the tumour cells to a changed tissue micro-environment. Considering that little experimental data exists on the biological behaviour of early seminoma cells this study adds information to the present knowledge of their proliferation kinetics.