Morphology of ovarian mucinous cystadenoma: surface ultrastructure, development and biologic behavior.

Thirty mucinous cystadenomas, borderline tumors and cystadenocarcinomas were analyzed by scanning and transmission electron microscopy. Results were compared to those obtained by light microscopy. Benign tumors consisted of endocervical-type columnar, mucus-containing cells with microvilli and cilia, goblet cells and intestinal-type microvillous cells. Borderline tumors showed a decrease in number and size of specialized surface structures in relation to degree of cellular atypia, the number of nucleoli and nuclear indentations indicating areas of incipient malignancy. Invasive carcinomas consisted mainly of intestinal-like surface cells varying in size and shape in relation to degree of tumor differentiation.