A Case of Sterile Osteomyelitis: Chronic Recurrent Multifocal Osteomyelitis (CRMO)

Abstract

Chronic recurrent multifocal osteomyelitis (CRMO) is a rarely reported autoimmune inflammatory condition affecting children and young adults. The typical complaint is recurrent severe bone pain at multiple sites; often imaging suggests features of osteomyelitis or malignancy. However, the biopsy is always negative for any growth in culture and histopathology detects only inflammatory cells. This is a diagnosis of exclusion with various diagnostic criteria. We had a 20-year-old male presenting with recurring pain and swelling in the right hand and left foot for more than seven months. Imaging revealed bone marrow edema with the expansion of bone and sclerosis involving the third metacarpal of the right hand and first metatarsal of the left foot. Acute phase reactants were mildly raised with biopsy showing inflammatory cells. However, the cultures grown from the lesion were sterile. After comparing it with the various diagnostic criteria, a diagnosis of CRMO was made.

Keywords: bone disease; bone pain; chronic non-bacterial osteomyelitis; chronic recurrent multifocal osteomyelitis; chronic recurrent osteomyelitis; mri; nonbacterial osteomyelitis.

Figure 1. Chronic recurrent multifocal osteomyelitis (CRMO) in a 20-year-old male presented with recurrent right hand and left foot pain. Findings/technique- (a) Dorso-plantar radiograph of both feet showing widening of bone with subtle thickening of cortex and sclerosis involving the distal epiphysis, metaphysis, and diaphysis of the first metatarsal bone of the left foot. (b) Postero-anterior radiographs of both hands show similar features involving the shaft and distal end of the right third metacarpal with comparatively more evident sclerosis. The findings are more evident when compared to the contralateral normal side.

Figure 2. Chronic recurrent multifocal osteomyelitis (CRMO) in a 20-year-old male presented with recurrent left foot pain and swelling. Findings/technique- (a) coronal and (b) axial reformatted plain computed tomography (CT) image of the left foot showing widening of the bone, marked cortical thickening and hyperostosis due to chronic periosteal reaction in the first metatarsal bone.

Figure 3. Chronic recurrent multifocal osteomyelitis (CRMO) in a 20-year-old male presented with recurrent left foot pain and swelling. Findings/technique- Non-contrast MRI (3T) of left foot with PDFS sequences in (a) sagittal, (b) coronal and (c) axial sections showing hyperintense marrow signal involving first metatarsal bone with significant cortical thickening and associated adjacent soft tissue edema.

Figure 4. Chronic recurrent multifocal osteomyelitis (CRMO) in a 20-year-old male presented with recurrent right hand pain and swelling. Findings/technique- Non-contrast MRI(3T) of right hand on T1 weighted sequences in (a) coronal and PDFS sequences in (b) coronal, (c) sagittal and (d) axial plains showing hyperintense marrow signal involving third metacarpal with cortical thickening and widening of the bone. There is surrounding soft tissue inflammation and periosteal reaction.