P53 IMMUNOSTAINING SUGGESTS THAT UTERINE CARCINOSARCOMAS ARE MONOCLONAL

The histogenesis of carcinosarcomas has intrigued pathologists for a l ong time and remains unresolved. Two main theories have been put forwa rd, one suggesting that they are monoclonal, another suggesting that t hey are biclonal. Our study examined p53 immunostaining in 17 uterine carcinosarcomas (mixed Mullerian tumours) and found positivity in five (30%). There was no disparity in immunostaining between the epithelia l and the stromal components in any of the 17 tumours. This concordanc e in every tumour would be very unlikely if carcinosarcomas are biclon al; However, it would be expected if carcinosarcomas are monoclonal.