Cytopathology involves removing and examining cells from tissue and bodily fluids. Among other things, cells are removed for cancer detection either by injection or a smear. They are then examined under the microscope, assessed and classified into different stages. Among women, for example, smears of the cervix are regularly taken so as to allow early detection of cervical cancer. Other specimens taken include sputum, bronchial mucus, urine and biopsies from various organs such as the thyroid and the lymph nodes.