Abstract :
Cancers of unknown primary site (CUPs) are histologically confirmed metastatic carcinoma for which primary site cannot be identified after standard diagnostic approach. It comprises 3-4% of all malignant neoplasms. The broad tumour type for CUPs is carcinoma. Metastatic tumours are more difficult to classify than primaries by Immunohistochemistry (IHC). Integration of morphology & IHC is the gold standard at diagnosing CUP. It is important to be aware of possible pitfalls of IHC and pay attention to correct interpretation. One should have a working algorithmic approach to identifying and classifying CUPs.
Keyword :
Malignant neoplasm, Immunohistochemistry, Metastatic carcinoma, Cytokeratin.