Vaginal cancer. Light micrograph of a vaginal smear showing adenocarcinoma cells (centre). Adenocarcinoma is a form of cancerous tumour arising from glandular tissue. The tumour cells have large rounded nuclei (dark purple) that take up most of the volume of the cell, a sign that they are dividing rapidly. Vaginal cancer is rare, occurring most often in women over the age of 40. Smear tests are carried out routinely in adult women to try to detect cancer of the vagina and cervix at the earliest stages. Cervical cancer is more common. These diseases are more likely to be treated successfully if caught early. Papanicolaou stained. Magnification unknown.