Pediatric pelvic pyomyositis: initial MRI can be misleading.

Area of Science:

• Musculoskeletal infections
• Diagnostic imaging in orthopedics

Background:

• Pelvic pyomyositis is a rare infection of the hip girdle skeletal muscles.
• Common symptoms include fever, hip pain, and limping, but the presentation is often nonspecific.
• Magnetic resonance imaging (MRI) is the gold standard for diagnosing pyomyositis.

Purpose of the Study:

• To report a case of pelvic pyomyositis with an initially unremarkable MRI.
• To highlight the potential for misleading initial imaging findings in pyomyositis.
• To emphasize the importance of clinical correlation and repeat imaging.

Main Methods:

• Case report of an adolescent female with symptomatic pelvic pyomyositis.
• Initial MRI of the pelvis was normal.
• Follow-up MRI demonstrated findings consistent with pelvic pyomyositis.
• Successful nonoperative management was implemented.

Main Results:

• The initial MRI did not reveal evidence of pyomyositis.
• A subsequent MRI confirmed the development of pelvic pyomyositis.
• The patient recovered with conservative treatment.

Conclusions:

• Initial MRIs in cases of suspected pelvic pyomyositis can be normal and misleading.
• Clinical suspicion should guide management, including admission and repeat MRI if symptoms persist or worsen.
• Nonoperative management can be successful in selected cases of pelvic pyomyositis.