Clinicoradiological, Histopathological and Immunohistochemical Spectrum of Lung Lesions: An Observational Cross-sectional Study

Introduction: Pulmonary lesions encompass a wide spectrum of non-neoplastic and neoplastic conditions with overlapping clinical and radiological features, often posing diagnostic challenges. Histopathological examination remains the gold standard for definitive diagnosis, supported by immunohistochemistry for tumour subtyping and metastatic evaluation. Aim: The present study aimed to assess the clinicoradiological and histopathological spectrum of lung lesions received at a tertiary care hospital and to evaluate radiology-histopathology correlation. Materials and Methods: The present observational, descriptive, cross-sectional study was conducted at Dr. DY Patil Medical College, Hospital and Research Centre, Pimpri, Pune, from February 2024 to February 2026. A total of 110 lung specimens, including transbronchial biopsies, Computed Tomography (CT)-guided core biopsies, explant specimens, and resections, were analysed. Clinical presentation, radiological findings, histopathological diagnosis, and Immunohistochemical (IHC) profiling were recorded. Lesions were categorised as nonneoplastic or neoplastic and further classified according to World Health Organization (WHO) criteria. Results: The mean age of patients was 55.35±15.81 years, with male predominance (n=70, 63.64%). Cough (n=66, 60%) and breathlessness (n=64, 58.18%) were the most common symptoms. Non-neoplastic lesions constituted (n=70, 63.64%) cases, with Interstitial Lung Disease (ILD) being the most common (n=27, 38.57%). Neoplastic lesions accounted for (n=40, 36.36%), predominantly primary tumours (n=35, 87.5%). Adenocarcinoma was the most frequent malignancy (n=28, 70%), followed by neuroendocrine tumours (n=4, 10%) and squamous cell carcinoma (n=3, 7.5%). Immunohistochemistry (IHC) aided tumour characterisation and subtyping in primary lung neoplasms using markers such as Thyroid Transcription Factor 1 (TTF-1), Napsin A, Cytokeratin 7 (CK7), p63, and synaptophysin. In metastatic lesions, site-specific markers such as GATA-binding protein 3 (GATA3), Estrogen Receptor (ER), Progesterone Receptor (PR), Human Epidermal Growth Factor Receptor 2 (HER2/neu), Paired Box 8 (PAX8), and Cluster of Differentiation 10 (CD10) helped suggest the likely primary site of origin in selected cases. Radiological correlation showed high specificity but moderate sensitivity, with (n=11, 10%) cases reclassified after histopathology. Conclusion: Histopathology, supported by immunohistochemistry, remains essential for accurate diagnosis and classification of lung lesions, particularly in cases with radiological overlap. The findings highlight the need for a multidisciplinary approach integrating clinical, radiological, and pathological data for optimal patient management.