An undifferentiated malignant tumour on immunohistochemical stain shows cytoplasmic positivity of most of the tumor cells for cytokeratin. The most probable diagnosis of the tumor is?
Sarcoma
Lymphom
Carcinoma
Malignant Melanoma
Immunohistochemistry Immunohistochemistry is a method of analyzing and identifying cell types based on binding of antibodies to specific components of the cell.o Antibody, which is specific for an antigen of a paicular tissue, is labled with a probe (coloured marker) and is run on the tissue specimen obtained from a biopsy.o If the tissue has that paicular antigen, then antibody will get attached to the tissue and the labled antibody can be seen under a microscope.Intermediate filaments of cytoskeleton are the major antigens used in immunohistochemistry. o There are five major types of intermediate filaments -Cytokeratin Carcinoma, mesothelioma, Non-seminoma GCTVimentin Neurofilament Sarcoma (Tumor of mesenchymal), melanoma, seminomas, lymphoma Neural tumorsGnat fibrillary acid proteins (GFAP) Non-neural brain tissue (astroglial origin --> Astrocytoma, ependymomas, medulloblastoma, oligodendroglioma)Desmin Leiomyoma (smooth muscle) & Rhabdomyoma (skeletal ms).