Septic pulmonary embolism: Is it an underestimated diagnosis?

Background: Non-thrombotic pulmonary embolism, an uncommon entity, is defined as the embolization of tissues, microorganisms, air, or foreign material. One subset in this non-thrombotic category is septic pulmonary embolism (SPE) that refers to embolism of microorganisms with or without a thrombotic mantle into the pulmonary vasculature. This condition is often recognized on the basis of imaging with a clinical correlation. Unfortunately, data regarding the pathological features are meager. This has prompted to review such cases at autopsy.

Aims: To study the pathological features of SPE at autopsy.

Materials And Methods: Ten-year (2012 to 2021) autopsy records of the hospital were retrospectively reviewed. The diagnosis was based on the identification of acute necrotizing pulmonary arteritis with peri-bronchoarterial consolidation. These cases were analyzed with reference to the demographics, clinical characteristics, and pulmonary/extrapulmonary findings at autopsy.

Statistical Analysis: Nil.

Results: According to the inclusion criterion, 19 cases demonstrated the presence of SPE. There were 11 men and 8 women with a mean age of 32.1 years. The major source of infection included infection arising from skin and musculo-skeletal system (11 patients, 59.7%). The common clinical presentation included fever, dyspnea, chest pain, hemoptysis, and altered sensorium. The cause of death was mainly due to septicemia and/or confluent lung consolidations. A large number of bacterial colonies were seen in all; Candida species were also identified in two cases. Other lung findings included diffuse alveolar damage, fresh arterial thrombosis, infarction, arterial pseudo-aneurysms, abscess formation, and pyogenic pleuritis.

Conclusion: Presence of an extrapulmonary infection with persistent fever, bacteremia, and pulmonary complaints should raise suspicion for this entity, particularly in resource-poor settings, to prevent grave pulmonary complications.