Background Bronchogenic carcinoma refers to tumors originating in the lung parenchyma or within the bronchi. Broadly, they are classified into small cell and non-small cell lung carcinoma. Non-small cell is further divided into adenocarcinoma, squamous cell carcinoma and large cell carcinoma. Paraneoplastic syndromes (PNS) are defined as the signs and symptoms attributed to cytokines or hormones released from a tumour or a patient's immune system. PNS is found to play a role in the prognosis of the patient, as well as in some cases, a preceding event before cancer diagnosis. Through this study, we aim to shed light on the occurrence of different paraneoplastic syndromes among the types of bronchogenic carcinoma. Aim To assess the occurrence of various paraneoplastic syndromes in patients diagnosed with bronchogenic carcinoma. Materials and methods In a prospective study at the Department of Respiratory Medicine at Sri Ramachandra Institute of Higher Education and Research, we explored the occurrence of paraneoplastic syndromes in patients with bronchogenic carcinoma. We calculated the sample size using n-Master software version 2.0 (https://nmaster.software.informer.com/). Patients were classified based on the symptoms they experienced for neurological, musculoskeletal, hypercalcemia, Cushing syndrome, chronic gastrointestinal (GI) pseudo-obstruction, and limbic encephalitis. They were then graded based on the definitions of the new diagnostic criteria, 2021, as: Definite (high risk), Probable (intermediate risk), Possible (minimal risk), and No PNS. Further, the prevalence of PNS in each subtype of bronchogenic carcinoma was ascertained. Results The occurrence was found to be 35% in small cell
28% in large cell
20% in adenocarcinoma and 17% in squamous cell carcinoma. Further, Definite PNS was highest in small cell carcinoma, while No PNS was most prevalent in adenocarcinoma.