Giant cell carcinoma refers to the malignant epithelial neoplasm characterized by large undifferentiated cells. Small quantity of adenocarcinomas of the lung and liver has such types of cells. Giant cell carcinoma of the prostate has also been reported.
It is considered as the variant of large cell carcinoma and is an aggressive form of cancer. It has a very poor prognosis.
Giant cell carcinoma has the parts of highly pleomorphic multinucleated cells. It has different sizes of nuclei with large and irregular shapes containing clumped chromatin and one or more nucleoli. The nuclei are often multilobed.
Giant cells in this carcinoma lack the specific features of adenocarcinoma, squamous cell or large cell carcinoma. There may be multiple small nuclei within a cell having a large amount of finely vacuolated eosinophilic cytoplasm. They have no cell cohesion tending to dissociation of the cells from each other.
Often the necrotic component to these tumors results in neutrophilic or monocytic inflammatory cell infiltrate. This phenomenon is thought to represent the emperipolesis, i.e. active penetration of the leukocytes into the tumour cells.
Presence or absence of different proteins in the Giant Cell Carcinomas:
Immunohistochemical stains can help us in differentiation of these tumors from the other types as for example negative staining for mucin can help us to differentiate it from an adenocarcinoma and positive staining for cytokeratins is helpful in reducing the chances of sarcomas. Absence of cell cohesion shows lymphoma. Giant cell tumors have no leukocyte common antigen (CD45). These tumors are sometimes positive for humoan chorionic gonadotrophin (hCG) and may superficially resemble choriocarcinomas. Desmosomes are very occasionally seen in the giant cell carcinoma.
http://chemo.net/large.htm accessed February 10, 2013.
“Pathology & Genetics: Tumours of the Lung, Pleura, Thymus, and Heart” by “William D. Travis, M.D.”