Lung cancer. Light micrograph of a section through a lung with giant cell carcinoma. The cancerous cells, such as the one at center left, have abundant cytoplasm and large nuclei (dark purple). This is a type of undifferentiated large cell carcinoma. Cancer cells divide continuously, growing chaotically to form clumps of cells called tumors. Giant cell carcinoma is a malignant type of lung cancer, as it invades and destroys surrounding tissue, as well as migrating (metastasizing) to other parts of the body. Brightfield illumination. Magnification: x100 at 35 mm size.