The challenge of diagnosing psoas abscess

Area of Science:

• Medical Imaging
• Infectious Diseases
• Orthopedics

Background:

• Psoas abscess diagnosis can be difficult in patients presenting with low back pain and atypical symptoms.
• Initial diagnostic imaging, including computed tomography (CT) and abdominal sonography, may be inconclusive.

Observation:

• A 39-year-old male presented with acute low back pain, initially attributed to lumbar strain.
• Despite negative initial imaging, the patient developed fever, leukocytosis, and elevated C-reactive protein, leading to a diagnosis of fever of unknown origin (FUO).
• Persistent symptoms prompted further investigation with an inflammatory gallium scan and magnetic resonance imaging (MRI).

Findings:

• Gallium scan revealed active infection in the L4 vertebra and L5 paraspinal region.
• MRI demonstrated abnormal enhancement in the L2-L3 vertebrae, prevertebral soft tissue, and bilateral psoas muscles, confirming psoas abscess.
• CT-guided aspiration yielded pus but no pathogens; symptoms resolved with antibiotics.

Implications:

• This case highlights the importance of nuclear scanning and MRI in diagnosing psoas abscess, especially when initial imaging is inconclusive.
• It suggests considering repeated or alternative imaging modalities when clinical presentation is inconsistent with initial findings.
• Early and accurate diagnosis of psoas abscess is critical for effective treatment and patient recovery.