Genetic changes correlate with histopathology in a benign, borderline and malignant mucinous ovarian tumour

Mucinous Ovarian Tumors

Ovarian mucinous tumors range from benign cystadenomas to borderline tumors to frankly malignant adenocarcinomas, and may display either intestinal-type morphology or, less frequently, endocervical-type differentiation. The latter category has been the subject of recent controversy owing to its morphologic overlap with so-called "seromucinous" ovarian tumors, a group that shares more molecular features with endometrioid tumors than it does with either serous or mucinous ovarian neoplasias. Endocervical-type differentiation in ovarian mucinous tumors may also represent an endocervical metastasis. Distinction of primary ovarian mucinous tumors from gastrointestinal metastases can be difficult, as the morphology of intestinal-type ovarian mucinous primaries sometimes differs only subtly if at all from gastrointestinal metastases.

Novel population of small tumour-initiating stem cells in the ovaries of women with borderline ovarian cancer

Small stem cells with diameters of up to 5 μm previously isolated from adult human ovaries indicated pluripotency and germinal lineage, especially primordial germ cells, and developed into primitive oocyte-like cells in vitro. Here, we show that a comparable population of small stem cells can be found in the ovarian tissue of women with borderline ovarian cancer, which, in contrast to small stem cells in "healthy" ovaries, formed spontaneous tumour-like structures and expressed some markers related to pluripotency and germinal lineage. The gene expression profile of these small putative cancer stem cells differed from similar cells sorted from "healthy" ovaries by 132 upregulated and 97 downregulated genes, including some important forkhead box and homeobox genes related to transcription regulation, developmental processes, embryogenesis, and ovarian cancer. These putative cancer stem cells are suggested to be a novel population of ovarian tumour-initiating cells in humans.