Original article / research
Year : 2026 Month : April Volume : 15 Issue : 2 Page : PO01 - PO07 Full Version

Immunohistochemical Evaluation of TTF-1 Expression in Lung Carcinomas: A Cross-sectional Study from a Tertiary Care Centre, Hyderabad, Telangana, India
Muppidi Keerthana, Gudivada Venkata Sai Praneetha, Ventrapragada Lalitha
1. Associate Professor, Department of Pathology, CMR Institute of Medical Sciences, Hyderabad, Telangana, India. 2. Assistant Professor, Department of Pathology, CMR Institute of Medical Sciences, Hyderabad, Telangana, India. 3. Assistant Professor, Department of Pathology, CMR Institute of Medical Sciences, Hyderabad, Telangana, India.
 
Correspondence Address :
Muppidi Keerthana,
Villa No. 25, Anthem Villas, Gundlapochampally, Near Kompally, Medchal Road,
Hyderabad-500100, Telangana, India.
E-mail: keerthana1990@gmail.com
 
ABSTRACT
: Introduction: Lung cancer has been the most common cancer in the world for several decades. As a result of the identification of so many new therapeutic targets, the tissue samples are no longer managed for diagnosis alone, but also for immunohistochemical (IHC) staining and molecular testing. Thyroid Transcription Factor-1 (TTF-1) has been found in malignant tumours highly selectively in lung and thyroid cancers.

Aim: To evaluate the expression of TTF-1 in guided biopsies of primary lung carcinomas and assess its role in the histopathological diagnosis of various lung cancer subtypes.

Materials and Methods: This was an observational, cross-sectional, descriptive study conducted in the Department of Pathology, CMR Institute of Medical Sciences, Hyderabad, Telangana, India, over a period of two years and two months. A total of 50 {ultrasound-, Computed Tomography (CT)-, or bronchoscopy-guided} diagnosed as primary epithelial lung carcinomas were included. Autolysed, inadequate, benign, metastatic, and treated cases were excluded. All specimens were formalin-fixed, paraffin-embedded, and stained with Haematoxylin and Eosin (H&E). Confirmed malignant epithelial tumours were subjected to IHC for TTF-1. Data on age, gender, histological type of tumour, reaction with TTF-1 were analysed using descriptive statistics and expressed as frequencies and percentages.

Results: A total of 50 lung carcinoma cases were studied. The most common histological type was adenocarcinoma 15 (30%), followed by small cell carcinoma 10 (20%), Squamous Cell Carcinoma (SCC) 9 (18%), Non Small Cell Lung Carcinoma (NSCLC) favour adenocarcinoma 7 (14%), NSCLC favour SCC 3 (6%), NSCLC- Not Otherwise Specified (NOS) 3 (6%), adenosquamous carcinoma 2 (4%), and carcinoid 1 (2%). Males constituted 36 (72%) cases and females 14 (28%). The highest incidence occurred in the 61-70 year age group, 20 (40%), followed by the 51-60 years age group, 14 (28%). TTF-1 positivity was observed in 36 (72%) cases overall. All adenocarcinomas 15 (100%), all NSCLC favour adenocarcinoma 7 (100%), both adenosquamous carcinomas 2 (100%), the carcinoid tumour 1 (100%), and 8/10 (80%) small cell carcinomas showed positivity. TTF-1 was negative in 8/9 (89%) SCCs and all 3 (100%) NSCLC favour SCC cases. Among NSCLC-NOS, 2/3 (67%) cases were positive.

Conclusion: One of the great advances in the past decade in lung cancer diagnosis and treatment was the concept of personalised medicine, where therapeutic decisions are based on the specific histologic and genetic characteristics of the patient’s tumour.
Keywords : Adenocarcinoma lung, Immunohistochemistry, Lung cancer, Small cell carcinoma lung
DOI and Others : DOI: 10.7860/NJLM/2026/84577.2959 Date of Submission: Sep 25, 2025 Date of Peer Review: Nov 22, 2025 Date of Acceptance: Jan 08, 2026 Date of Publishing: Apr 01, 2026 AUTHOR DECLARATION: • Financial or Other Competing Interests: None • Was Ethics Committee Approval obtained for this study? Yes • Was informed consent obtained from the subjects involved in the study? Yes • For any images presented appropriate consent has been obtained from the subjects. No PLAGIARISM CHECKING METHODS: • Plagiarism X-checker: Oct 23, 2025 • Manual Googling: Jan 03, 2026 • iThenticate Software: Jan 06, 2026 (5%) ETYMOLOGY: Author Origin EMENDATIONS: 6
 
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