Undifferentiated pancreatic carcinomas are rare anaplastic variants of ductal adenocarcinoma of the pancreas. They have to be distinguished immunohistochemically from metastases of malignant melanoma or an infiltrating sarcoma. An uncommon variant is undifferentiated pancreatic carcinoma with osteoclast-like giant cells. This variant can be associated with mucinous cystic neoplasms and is characterized by abundant non-neoplastic osteoclast-like giant cells.