Background: So far lung carcinoma is the 2nd most prevalent cancer in both male and female and remains one of the leading cause of death in the world. With recent advancements in molecular testing and Immunohistochemistry (IHC), it has been possible to subtype various lung carcinomas. The combination of histopathological classification and Immunohistochemistry provides clinical insight into the management of these patient. Napsin-A and TTF-1 are two IHC markers with the potential to help us differentiate primary from metastatic lung carcinoma.
Materials and Methods: The present study was carried out on 108 patients. Types of samples include lung biopsy specimens received in histopathology section of the pathology department. The cases were diagnosed based on light microscopy and immunohistochemistry procedure with Napsin-A and TTF-1 antibodies was performed.
Aims and Objectives
To determine the incidence of primary lung adenocarcinoma as compared to other lung malignancy.
To use Immunohistochemistry markers, Napsin-A and TTF-1, for differentiating primary lung malignancy from metastatic lung cancer.
Results: A total of 108 lymph node specimens were studied. Age distribution varied from 35-82 years with male preponderance. Out of 65 cases of adenocarcinoma of lung, 53 (81.5%) expressed both Napsin-A and TTF-1 positivity, 07 (10.7%) were Napsin-A positive but TTF-1 negative while 05 (07.6%) were negative for both the markers. Out of 03 cases of adenosquamous carcinoma, 01 (33.3%) was Napsin-A positive, TTF-1 negative while 02 (66.7%) were negative for both. There were 06 cases of squamous cell carcinoma, 01 (16.7%) showed TTF-1 positivity but negative for Napsin A, while 05 (83.3%) expressed none of the markers. Out of 25 cases of secondaries to lung, 12 (48%) expressed TTF-1 positivity only while 13 (52%) expressed none of the two markers.
Conclusion: Performing an IHC with dual markers Napsin A and TTF-1 increases the sensitivity of detecting primary lung malignancy.