Ovarian cancer. Coloured scanning electron micro- graph (SEM) of cancer cells in the human ovary. These tumour cells are a variety of shapes and sizes, typical of the chaotic arrangement and growth of malignant cancer cells. The cells are covered with fine surface protrusions called microvilli. The most common type of ovarian cancer is carcinoma, developing from surface epithelial cells. Ovarian cancer is most common in women over age 50 and in women who have never had children, and less common in women who have taken oral contraceptives. Treatment involves surgical removal of the tumour tissue, followed by radio- therapy & anticancer drugs. Magnification unknown.