Background: Thoracic aortic aneurysms, particularly those involving the descending thoracic aorta, are uncommon and frequently remain clinically silent until catastrophic rupture. Saccular aneurysms represent a rare morphological subtype and are believed to carry a higher risk of rupture compared with fusiform aneurysms, yet they are often underrecognized in clinical practice.

Case Description: We report an autopsy-based analysis of a 56-year-old male with a history of hypertension and diabetes mellitus who experienced sudden collapse and was declared dead on arrival. There were no preceding symptoms suggestive of cardiovascular or neurological disease. Postmortem examination revealed massive left-sided hemothorax (2750 g) secondary to rupture of a saccular aneurysm of the descending thoracic aorta. A transverse tear measuring 2.5 cm was identified, associated with a DeBakey type III aortic dissection extending distally.

Pathological Findings: Gross examination demonstrated a thin-walled saccular aneurysm with mural thrombus. Histopathological evaluation showed medial degeneration with necrosis, fibrosis, fibrin deposition, hyalinization, and mixed inflammatory infiltrates at the rupture site. Additional findings included advanced atherosclerosis of the aorta and features of healed myocardial infarction, highlighting underlying chronic cardiovascular pathology.

Discussion: This case underscores the deceptive and lethal nature of descending thoracic saccular aneurysms, which may remain asymptomatic despite significant rupture risk. Sudden death in such cases is frequently misattributed to myocardial infarction or cerebrovascular events, leading to underestimation of true disease prevalence.

Conclusion: Early recognition and proactive monitoring of high-risk individuals, particularly those with hypertension, are crucial. Autopsy findings play a vital role in elucidating hidden cardiovascular causes of sudden death and emphasize the need for improved diagnostic strategies to prevent fatal outcomes.

Dr. Jayeshkumar Kanani has over 14 years of experience including 8 years of experience in the field of forensic medicine and Toxicology. Appointed in 2016 as an autopsy medical officer, he has conducted over 4,000 autopsies, providing invaluable medico-legal expertise in death investigations. His expertise extends to histopathological studies, scientific writing, court testimonies, and mentoring students in forensic medicine. Dr. Kanani has published many peer-reviewed papers in international journals such as Elsevier, BMC, and SpringerNature, with most as the first author. He has demonstrated exceptional skill in managing the publication process, and successfully publishing articles with tight deadlines. His research interests include general medicine, forensic medicine, Toxicology, Surgery, Cardiology, Pathology, Oncology, and Neurology. He is passionate about contributing to the academic and professional community and welcomes opportunities to collaborate on research and editorial endeavours