A 67 yr male with history of chronic smoking hemoptysis with cough. Bronchoscopic biopsy from centrally located mass shows undifferentiated tumor histopathologically. Most useful I.H.C. (immunohistochemical) marker to make a proper diagnosis would be: (AIIMS Nov 2014)
' The presence of chronic smoking cough and hemoptysis in old man is a pointer towards a diagnosis of bronchogenic cancer. The central location suggests the possibility of a squamous cell cancer.
Robbins writes “Histologically, this tumor is characterized by the presence of keratinization and/or intercellular bridges
• HMB-45 is a specific tumor marker for melanoma.
• Parvalbumin is low molecular binding albumin protein localized in fast-contracting muscles. It is also present in the brain (in GABAergic interneurons) and some edocrine tissue. Decreased PV and GAD67 expression was found in PV+GABAergic interneurons in schizophrenia.
• Hep-par 1 is hepatocyte paraffin 1 and is well known marker for hepatocellular carcinoma