Osteomyelitis is an inflammation of the bone typically caused by infection. Staphylococcus is responsible for most cases of osteomyelitis. Chronic osteomyelitis results from a longstanding infection, on average longer than 6 weeks. Chronic osteomyelitis typically results in sclerosis. Our patient, however, had lytic destruction, not sclerotic destruction. The differential diagnosis for multiple lytic lesions in an adult is metastatic disease or multiple myeloma. An infectious process such as osteomyelitis is not usually included in the differential diagnosis. In addition, it is uncommon for an adult to have multiple areas affected by ostemyelitis, as seen in our patient, compared to the pediatric population.
Our patient had no history of immune deficiency disorders, sickle cell anemia, IV drug abuse, diabetes mellitus or subacute bacterial endocarditis, which all increase the risk of multifocal bacterial osteomyelitis. Pathological fractures are not common in osteomyelitis, especially in cases without devastating septicemia. Our patient had negative blood cultures throughout his 10-day hospital stay. Our patient also had no prior history of osteomyelitis, which has been theorized to increase the risk of pathological fractures. The source of our patient's initial infection is unknown. It is uncertain if our patient had osteomyelitis leading to the multiple soft-tissue abscesses, or if the soft-tissue abscesses led to the osteomyelitis. It is also unclear why the bony infections led to lytic destruction of the humeral head and pathological expansile fractures of the pubic rami in such a short time (less than 2 years).
Appl Radiol. 2015;44(9):46-47. © 2015 Anderson Publishing, Ltd.