Subclassification of pulmonary non-small cell lung carcinoma in fine needle aspirates using a limited immunohistochemistry panel

Abstract

Background:Newer treatment modalities require subtyping of non-small cell lung carcinomas (NSCLC). Morphological differentiation is often difficult and various immunohistochemical (IHC) panels have been used to maximize the proportion of accurately subtyped NSCLC.Aim:The aim of this study was to subtype NSCLC on fine needle aspirates (FNA) using a minimal antibody panel.Materials and Methods:Cell blocks from 23 FNA samples with a morphological diagnosis of NSCLC were taken. IHC was evaluated (blinded to clinical data) for thyroid transcription factor-1 (TTF-1), cytokeratin (CK)7, CK20, and tumor protein p63.Results:TTF-1 was positive in 14 and negative in 9 cases. The p63 was positive in two cases each of TTF-1 positive and negative tumors. CK7 was positive in 12 of the 14 TTF-1 positive tumors and 4 of the TTF-1 negative tumors. CK20 was negative in all. All the 14 TTF-1 positive tumors were primary lung tumors, 12 being NSCLC and 2 being squamous cell carcinoma. Five of nine TTF-1 negative tumors were metastatic tumors from endometrium, kidney, and head and neck region (two), and one was an unknown primary. Four of the nine TTF-1 negative tumors were morphologically NSCLC and were clinically considered to be primary lung tumors. Three of these tumors stained positive for CK7 but negative for CK20 and p63, and one case was negative for the immunomarkers.Conclusion:Use of limited IHC panel helps categorize primary versus secondary tumors to the lung. The p63 is a useful marker for detecting squamous cell carcinoma. In countries where antibodies are not readily available, using a limited IHC panel of TTF-1, p63, and CK7 can help further type NSCLC lung tumors.

Comparison of immunohistochemistry and mRNA in situ hybridization in detecting thyroid transcription factor-1 expression in non-small cell lung carcinomas tissue

“…The expression patterns of TTF-1 protein and mRNA in the present study are consistent with those of our previous studies (10,11). TTF-1 and p63 immunostaining has been utilized successfully in previous studies (20,21) to facilitate pathological differentation between small cell carcinoma and poorly differentiated pulmonary SCC using cytological samples. Kapila et al (20) were able to catergorize NSCLC samples using a restricted panel of antibodies.…”

“…TTF-1 and p63 immunostaining has been utilized successfully in previous studies (20,21) to facilitate pathological differentation between small cell carcinoma and poorly differentiated pulmonary SCC using cytological samples. Kapila et al (20) were able to catergorize NSCLC samples using a restricted panel of antibodies. The authors were also able to differentiate between adenocarcinoma and SCC samples.…”

Profile of IHC Marker in Lung Tumours

“…In a study by Kusum Kapila et al CK5/6 showed a sensitivity and specificity of 53% and 96% respectively and TTF-1 was found to be most specific marker for adenocarcinoma with 60% sensitivity and 98% specificity. [25] Another study by Gregorz T Gurda et al in 72 cases of primary adencarcinoma TTF-1 showed a sensitivity and specificity of 84.5% and 96.4% respectively. In 30 cases of squamous cell carcinomaCK5/6 showed a sensitivity and specificity of 100% and 77.8% respectively [26].…”

Study of Pleural Effusions in Patients Attending Katuri Medical College & Hospital, Chinakondrupadu, Guntur, Andhra Pradesh

“…With the advent of targeted therapy for advanced lung carcinomas and significant differential response to them, it is recommended to further classify NSCLC into Adenocarcinoma and Squamous cell carcinoma based on morphology and ancillary techniques like IHC [immunohistochemistry] for the eligibility to Targeted therapy. [19,20] When the morphological criteria of Squamous cell carcinoma and Adenocarcinoma were present, diagnosis can be easily established. When the tumour does not show the classical morphological criteria, immunohistochemical work up is necessary for further typing.…”