Undifferentiated Carcinoma
Mari Mino-Kenudson, MD
Key Facts
Terminology
Malignant epithelial neoplasm with significant component showing no definite differentiation
Wide range of morphologic findings ranging from pleomorphic epithelioid cells to multinucleated giant cells to spindle cells
Clinical Issues
Rare
Prognosis is dismal
Macroscopic Features
Large, fleshy mass, often with hemorrhage and necrosis, that invades adjacent organs
Microscopic Pathology
Heterogeneous features consisting of anaplastic giant cell and spindle cell components in varying proportions
Variably present large, benign-appearing, multinucleated osteoclast-like giant cells
 This gross photograph of an undifferentiated carcinoma with osteoclast-like giant cells has a soft, fleshy cut surface with prominent hemorrhage  and necrosis  . |
 This undifferentiated carcinoma has a prominent sarcomatoid component featuring plump spindle cells in a fascicular pattern. |
TERMINOLOGY
Synonyms
Pleomorphic carcinoma, pleomorphic large cell carcinoma, pleomorphic giant cell carcinoma
Undifferentiated carcinoma with osteoclast-like giant cells
Giant cell tumor of pancreas
Osteoclast-like giant cell tumor of pancreas
Definitions
Malignant epithelial neoplasm with significant component showing no definite differentiation
Wide range of morphologic findings ranging from pleomorphic epithelioid cells to multinucleated giant cells to spindle cells
Multiple patterns often present within same tumor
