Fatal pyomyositis: a report of 8 autopsy cases

Pyomyositis is an acute bacterial infection manifesting as pyemic abscess formation in the skeletal muscles. We examined 8 autopsy cases (seven males, one female; age range 21-75 years) of fatal nontropical pyomyositis to better describe individual case characteristics and pathologic features of this rare disease. The pathogen most frequently involved was Staphylococcus aureus. In most cases, there were several abscesses and multiple sites involved. The trunk, shoulder girdle, and thigh muscles were most frequently affected and involvement of multiple sites was a common finding. In 6 cases, a recent trauma had occurred to the anatomic location where the pyemic abscesses were found. Three deceased were known as intravenous drug abusers. Except for the presence of pyomyositis, liver diseases such as cirrhosis in 3 cases, and a fatty liver in 2 cases were the most frequent autopsy findings. Death was due to sepsis in all cases. Because pyomyositis may develop in association with intravenous catheterization in the clinical setting, the question whether pyomyositis was caused by an infected or improperly placed indwelling intravenous catheter may be of forensic importance in the light of alleged medical malpractice. According to our observations, severe underlying illnesses seem not always necessary for fatal outcome of pyomyositis. Because a detailed dissection of superficial as well as deep skeletal muscles during autopsy is a prerequisite for the diagnosis, the disease may be overlooked when this essential step is not performed.