Immunohistochemistry in carcinoma of unknown primary site: Practical application
C S Banushree*Indira Gandhi Government Medical College and Research Institute, IndiaCitation:
C S Banushree (2018) Immunohistochemistry in carcinoma of unknown primary site: Practical application, SciTech Oncology 2019, Dubai, UAE
Received: December 01, 2018 Accepted: December 03, 2018 Published: December 03, 2018
Cancers of unknown primary sites (CUPs) are histologically confirmed metastatic carcinoma for which primary site cannot be identified after standard diagnostic approach. It constitutes 3-4% of all malignant neoplasms. The gold standard at diagnosing CUPs is by integration of morphology & immunohistochemistry (IHC). The commonest histological subtype of CUPs is adenocarcinoma (60%). Metastatic tumours are more difficult to classify than primaries by IHC. We should have a working algorithmic approach to identifying and classifying CUPs. Two classes of antibody markers can be of assistance in the workup of CUP (a)antibodies to keratins, and (b) antibodies to organ-restricted and specific markers. There can be difficulties while working up for CUPs as the specimens are usually small. CK7 and CK20 have been most widely used to predict primary site. Some of the organ restricted and specific markers used in CUPs are TTF1, GATA3, PAX8, WT1, CDX2, SATB2, HepPar1 and PSA. This presentation will enlighten about the complex multi-step diagnostic procedure with pitfalls used in CUPs with individual approach to each Case scenario.
Keywords: Metastasis; adenocarcinoma; cytokeratins; transcription factors.