Fatal Pulmonary Air Emboli Associated with Pneumatosis Intestinalis

A 19-month-old patient died suddenly and unexpectedly ~11 months after hematopoietic stem cell transplantation (HSCT) for Hurler syndrome. Post-mortem examination revealed pulmonary air emboli that were attributed to extensive colonic pneumatosis intestinalis, an uncommon but reported complication of HSCT. Gas emboli are not just the result of trauma or decompression sickness but are more commonly iatrogenic in origin, resulting from the procedural-related introduction of air into the vascular system; pneumatosis intestinalis has rarely been associated with air emboli. Pathologists should be cognizant of unusual complications of HSCT and maintain a high index of suspicion for air embolization, even in a medically complex patient, to ensure optimal autopsy examination.