Loss of heterozygosity (LOH) affects a number of chromosome regions in ovarian cancer, pointing to the possible involvement of tumour‐suppressor genes in ovarian tumorigenesis. We performed comparative analysis of allelic loss at 6 frequently affected chromosome regions in a panel of 53 benign, borderline and malignant ovarian tumours. Precursor lesions could provide evidence that an accumulation of genetic events is required for normal ovarian epithelium to generate malignant tumours. LOH on chromosome 1p was relatively common in benign, borderline and malignant tumours, while at 11p and 7q it was observed not only in invasive but also in borderline tumours. Moreover, 17q and 18q were affected mainly in advanced malignant tumours and revealed a high frequency of clonal intratumoral heterogeneity. We encountered different spectra of genetic alterations in primary tumours and their metastasis, which may be the results of intratumoral heterogeneity leading to dissemination in only some sub‐clones. Int. J. Cancer 82:822–826, 1999. © 1999 Wiley‐Liss, Inc.

Loss of heterozygosity (LOH) affects a number of chromosome regions in ovarian cancer, pointing to the possible involvement of tumour-suppressor genes in ovarian tumorigenesis. We performed comparative analysis of allelic loss at 6 frequently affected chromosome regions in a panel of 53 benign, borderline and malignant ovarian tumours. Precursor lesions could provide evidence that an accumulation of genetic events is required for normal ovarian epithelium to generate malignant tumours. LOH on chromosome 1p was relatively common in benign, borderline and malignant tumours, while at 11p and 7q it was observed not only in invasive but also in borderline tumours. Moreover, 17q and 18q were affected mainly in advanced malignant tumours and revealed a high frequency of clonal intratumoral heterogeneity. We encountered different spectra of genetic alterations in primary tumours and their metastasis, which may be the results of intratumoral heterogeneity leading to dissemination in only some sub-clones. Int. J. Cancer 82:822-826, 1999.1999 Wiley-Liss, Inc.

In this article there are considered current views on biology of ovarian serous borderline tumors, there is presented a modern histological classification of 2014, which has undergone some changes. Variants of serous borderline tumors are described in terms of morphology, clinical course and prognosis. Also there is discussed the issue of the pathogenesis in the development of ovarian borderline tumors, the contribution of gene mutations in the occurrence of borderline, poorly or well differentiated ovarian tumors. There are described in details features of morphology of serous borderline tumors, the interrelationship of their occurrence and dedifferentiation in dependence on the molecular and genetic deteriorations. In the article there is considered the microinvasive version of the serous borderline tumors and specified criteria for the establishment of this diagnosis. There are given the definition and characterization of micropapillary serous borderline tumors, there is discussed their impact on the course of the disease and prognosis. The issue of terminology is considered in terms of current views and history.