Histopathological Analysis of Lung Lesions in Cases of Sudden Death: An Autopsy-based Study

Introduction: Cardiovascular and respiratory causes account for the major chunks in sudden death cases in various Western studies. Overall, a very limited number of studies have been conducted on respiratory system changes in cases investigated as sudden and unknown death in India. Pathological respiratory findings are said to be common in the autopsy population; however, their nature and prevalence are not well documented. Aim: To document the morphologic changes in lungs (both gross and microscopic) in cases of sudden death. Materials and Methods: The present study was a cross-sectional, prospective, and observational study conducted over a period of 12 months from 1st April 2010 to 31st March 2011. It was conducted on autopsy lung specimens received in the Department of Pathology, RG Kar Medical College and Hospital, Kolkata, West Bengal, India. For the purpose of present study, sudden death was defined as death occurring within 24 hours of the onset of the terminal symptoms. Unidentified subjects who were declared “Brought Dead” at the emergency room were also included in the study. The lungs were fixed in 10% formalin, weighed, and dimensions measured. Grossly, the lungs were examined for colour, volume, consistency, presence of any pathological changes, the status of bronchi and pleura, and findings were recorded. After routine processing and paraffin embedding, histological sections were stained with Haematoxylin and Eosin (H&E) stain and special stains as and when necessary. All the histological sections were examined microscopically, and findings were recorded. The obtained data were subjected to appropriate statistical analysis by entering the data in Microsoft (MS) excel 2010. Results: There were 46 males (88.46%) and 6 females (11.54%). The age range was 26-86 years, with a mean age of 51.02 years. Among the 52 cases, significant pulmonary pathology was found in 26 cases (50%), excluding postmortem changes. Extensive fibrocaseous pulmonary Tuberculosis (TB) 15 (28.85%) was the most common pulmonary lesion found, present in all age groups. The other major pathological lesions encountered were lobar pneumonia 4 (7.69%), emphysema 3 (5.77%), bronchopneumonia 2 (3.85%), etc. Conclusion: A significant number of cases with pathological lesions in the lung were detected during the histopathological examination of sudden death cases. All the lesions may or may not have contributed to death in a direct or indirect way. The undetected lung pathologies emphasise the importance of autopsy in cases of sudden death.