Light micrograph of pleomorphic cells. Pleomorphism refers to variation in the size and shape of cells, as is often seen in malignant tumours. These cancer cells exhibit such pleomorphism. The cells consist of nuclei (dark purple) containing prominent nucleoli (round dots inside nuclei) an eosinophilic (pink) cytoplasm. Haematoxylin and eosin stained tissue section. Magnification: 400x when printed at 10cm.