Representative examples of the undifferentiated carcinomas of the pancreas included in this study (H&E, ×200). (a) Undifferentiated carcinoma with osteoclast-like giant cells; some cases also contained anaplastic giant cells (inset) (H&E, ×200); (b) Undifferentiated carcinoma containing sheets of medium-to-large anaplastic cells (anaplastic carcinoma); in some cases, the malignant cells contained abundant pink cytoplasm creating a rhabdoid appearance (inset) (H&E, ×200). (c) Five cases contained epithelioid cells admixed with anaplastic cells that formed vague nests and trabeculae (H&E, ×200).